The equation of the directrix of a hyperbola is x – y + 3 = 0. Its focus is (-1, 1) and eccentricity 3. Find the equation of the hyperbola.
Given: Equation of directrix of a hyperbola is x – y + 3 = 0. Focus of hyperbola is (-1, 1) and eccentricity (e) = 3
To find: equation of the hyperbola
Let M be the point on directrix and P(x, y) be any point of the hyperbola
Formula used:
where e is an eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 2{x2 + 1 + 2x + y2 + 1 – 2y} = 9{x2 + y2+ 9 + 6x – 6y – 2xy}
⇒ 2x2 + 2 + 4x + 2y2 + 2 – 4y = 9x2 + 9y2+ 81 + 54x – 54y – 18xy
⇒ 2x2 + 4 + 4x + 2y2– 4y – 9x2 - 9y2 - 81 – 54x + 54y + 18xy = 0
⇒ – 7x2 - 7y2 – 50x + 50y + 18xy – 77 = 0
⇒7x2 + 7y2 + 50x – 50y – 18xy + 77 = 0
This is the required equation of hyperbola
In each of the following find the equations of the hyperbola satisfying the given conditions
vertices (0, ± 6),
Given: Vertices (0, ±6),
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Coordinates of the vertices for a standard hyperbola is given by (0, ±b)
According to question:
b = 6 ⇒ b2 = 36
We know,
a2 = b2(e2 – 1)
⇒ a2 = 64
Hence, equation of hyperbola is:
Find the equation of the hyperbola whose
focus is (0, 3), directrix is x + y – 1 = 0 and eccentricity = 2
Given: Equation of directrix of a hyperbola is x + y – 1 = 0. Focus of hyperbola is (0, 3) and eccentricity (e) = 2
To find: equation of the hyperbola
Let M be the point on directrix and P(x, y) be any point of the hyperbola
Formula used:
where e is an eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 2{x2 + y2 + 9 – 6y} = 4{x2 + y2 + 1 – 2x – 2y + 2xy}
⇒ 2x2 + 2y2 + 18 – 12y = 4x2 + 4y2+ 4 – 8x – 8y + 8xy
⇒ 2x2 + 2y2 + 18 – 12y – 4x2 – 4y2 – 4 – 8x + 8y – 8xy = 0
⇒ – 2x2 – 2y2 – 8x – 4y – 8xy + 14 = 0
⇒ -2(x2 + y2 – 4x + 2y + 4xy – 7) = 0
⇒ x2 + y2 – 4x + 2y + 4xy – 7 = 0
This is the required equation of hyperbola
Find the equation of the hyperbola whose
focus is (1, 1), directrix is 3x + 4y + 8 = 0 and eccentricity = 2
Given: Equation of directrix of a hyperbola is 3x + 4y + 8 = 0. Focus of hyperbola is (1, 1) and eccentricity (e) = 2
To find: equation of hyperbola
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 25{x2 + 1 – 2x + y2 + 1 – 2y} = 4{9x2 + 16y2+ 64 + 24xy + 64y + 48x}
⇒ 25x2 + 25 – 50x + 25y2 + 25 – 50y = 36x2 + 64y2 + 256 + 96xy + 256y + 192x
⇒ 25x2 + 25 – 50x + 25y2 + 25 – 50y – 36x2 – 64y2 – 256 – 96xy – 256y – 192x = 0
⇒ – 11x2 – 39y2 – 242x – 306y – 96xy – 206 = 0
⇒11x2 + 39y2 + 242x + 306y + 96xy + 206 = 0
This is the required equation of hyperbola
Find the equation of the hyperbola whose
focus is (1, 1) directrix is 2x + y = 1 and eccentricity =
Given: Equation of directrix of a hyperbola is 2x + y – 1 = 0. Focus of hyperbola is (1, 1) and eccentricity (e) =
To find: equation of hyperbola
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 5{x2 + 1 – 2x + y2 + 1 – 2y} = 3{4x2 + y2+ 1 + 4xy – 2y – 4x}
⇒ 5x2 + 5 – 10x + 5y2 + 5 – 10y = 12x2 + 3y2 + 3 + 12xy – 6y – 12x
⇒ 5x2 + 5 – 10x + 5y2 + 5 – 10y – 12x2 – 3y2 – 3 – 12xy + 6y + 12x = 0
⇒ – 7x2 + 2y2 + 2x – 4y – 12xy + 7 = 0
⇒7x2 – 2y2 – 2x + 4y + 12xy – 7 = 0
This is the required equation of hyperbola.
Find the equation of the hyperbola whose
focus is (2, -1), directrix is 2x + 3y = 1 and eccentricity = 2
Given: Equation of directrix of a hyperbola is 2x + 3y – 1 = 0. Focus of hyperbola is (2, -1) and eccentricity (e) = 2
To find: equation of hyperbola
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 13{x2 + 4 – 4x + y2 + 1 + 2y} = 4{4x2 + 9y2 + 1 + 12xy – 6y – 4x}
⇒ 13x2 + 52 – 52x + 13y2 + 13 + 26y = 16x2 + 36y2 + 4 + 48xy – 24y – 16x
⇒ 13x2 + 52 – 52x + 13y2 + 13 + 26y – 16x2 – 36y2 – 4 – 48xy + 24y + 16x = 0
⇒ – 3x2 – 23y2 – 36x + 50y – 48xy + 61 = 0
⇒3x2 + 23y2 + 36x – 50y + 48xy – 61 = 0
This is the required equation of hyperbola.
Find the equation of the hyperbola whose
focus is (a, 0), directrix is 2x + 3y = 1 and eccentricity = 2
Given: Equation of directrix of a hyperbola is 2x – y + a = 0. Focus of hyperbola is (a, 0) and eccentricity (e) =
To find: equation of hyperbola
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ 117{x2 + a2 – 2ax + y2} = 16{4x2 + y2 + a2 – 4xy – 2ay + 4ax}
⇒ 117x2 + 117a2 – 234ax + 117y2 = 64x2 + 16y2 + 16a2 – 64xy – 32ay + 64ax
⇒ 117x2 + 117a2 – 234ax + 117y2 – 64x2 – 16y2 – 16a2 + 64xy + 32ay – 64ax = 0
⇒ 53x2 + 101y2 – 298ax + 32ay + 64xy + 111a2 = 0
This is the required equation of hyperbola.
Find the equation of the hyperbola whose
focus is (2, 2), directrix is x + y = 9 and eccentricity = 2
Given: Equation of directrix of a hyperbola is x + y – 9 = 0. Focus of hyperbola is (2, 2) and eccentricity (e) = 2
To find: equation of hyperbola
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab &
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ac}
⇒ x2 + 4 – 4x + y2 + 4 – 4y = 2{x2 + y2 + 81 + 2xy – 18y – 18x}
⇒ x2 – 4x + y2 + 8 – 4y = 2x2 + 2y2 + 162 + 4xy – 36y – 36x
⇒ x2 – 4x + y2 + 8 – 4y – 2x2 – 2y2 – 162 – 4xy + 36y + 36x = 0
⇒ – x2 – y2 + 32x + 32y + 4xy – 154 = 0
⇒x2 + y2 – 32x – 32y + 4xy + 154 = 0
This is the required equation of hyperbola.
Find the eccentricity, coordinates of the foci, equations of directrices and length of the latus-rectum of the hyperbola.
9x2 – 16y2 = 144
Given: 9x2 – 16y2 = 144
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
9x2 – 16y2 = 144
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (±ae, 0)
Equation of directrix are:
Length of latus rectum is
Here, a = 4 and b = 3
⇒ c = 5
Therefore,
Foci: (±5, 0)
Equation of directrix are:
Length of latus rectum,
Find the eccentricity, coordinates of the foci, equations of directrices and length of the latus-rectum of the hyperbola.
16x2 – 9y2 = -144
Given: 16x2 – 9y2 = -144
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (0, ±be)
The equation of directrix are:
Length of latus rectum is
Here, a = 3 and b = 4
⇒ c = 5
Therefore,
Foci: (0, ±5)
The equation of directrix are:
Length of latus rectum,
Find the eccentricity, coordinates of the foci, equations of directrices and length of the latus-rectum of the hyperbola.
4x2 – 3y2 = 36
Given: 4x2 – 3y2 = 36
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = 3 and b =
Therefore,
The equation of directrix are:
Length of latus rectum,
= 8
Find the eccentricity, coordinates of the foci, equations of directrices and length of the latus-rectum of the hyperbola.
3x2 – y2 = 4
Given: 3x2 – y2 = 4
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = and b = 2
Therefore,
The equation of directrix are:
Length of latus rectum,
Find the eccentricity, coordinates of the foci, equations of directrices and length of the latus-rectum of the hyperbola.
2x2 – 3y2 = 5
Given: 2x2 – 3y2 = 5
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = and b =
Therefore,
The equation of directrix are:
Length of latus rectum,
Find the axes, eccentricity, latus-rectum and the coordinates of the foci of the hyperbola 25x2 – 36y2 = 225.
Given: 2x2 – 3y2 = 5
To find: eccentricity(e), coordinates of the foci f(m,n), equation of directrix, length of latus-rectum of hyperbola.
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = 3 and b =
Therefore,
The equation of directrix are:
Length of latus rectum,
Find the centre, eccentricity, foci and directions of the hyperbola
16x2 – 9y2 + 32x + 36y – 164 = 0
Given: 16x2 – 9y2 + 32x + 36y – 164 = 0
To find: center, eccentricity(e), coordinates of the foci f(m,n), equation of directrix.
16x2 – 9y2 + 32x + 36y – 164 = 0
⇒ 16x2 + 32x + 16 – 9y2 + 36y – 36 – 16 + 36 – 164 = 0
⇒ 16(x2 + 2x + 1) – 9(y2 – 4y + 4) – 16 + 36 – 164 = 0
⇒ 16(x2 + 2x + 1) – 9(y2 – 4y + 4) – 144 = 0
⇒ 16(x + 1)2 – 9(y – 2)2 = 144
Here, center of the hyperbola is (-1, 2)
Let x + 1 = X and y – 2 = Y
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = 3 and b = 4
Therefore,
⇒ X = ±5 and Y = 0
⇒ x + 1 = ±5 and y – 2 = 0
⇒ x = ±5 – 1 and y = 2
So, Foci: (±5 – 1, 2)
Equation of directrix are:
Find the centre, eccentricity, foci and directions of the hyperbola
x2 – y2 + 4x = 0
Given: x2 – y2 + 4x = 0
To find: center, eccentricity(e), coordinates of the foci f(m,n), equation of directrix.
x2 – y2 + 4x = 0
⇒ x2 + 4x + 4 – y2 – 4 = 0
⇒ (x + 2)2 – y2 = 4
Here, center of the hyperbola is (2, 0)
Let x – 2 = X
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci are given by (±ae, 0)
The equation of directrix are
Length of latus rectum is
Here, a = 2 and b = 2
Therefore,
⇒ and y = 0
⇒ and y = 0
⇒ and y = 0
Equation of directrix are:
Find the centre, eccentricity, foci and directions of the hyperbola
x2 – 3y2 – 2x = 8
Given: x2 – 3y2 – 2x = 8
To find: center, eccentricity(e), coordinates of the foci f(m,n), equation of directrix.
x2 – 3y2 – 2x = 8
⇒ x2 – 2x + 1 – 3y2 – 1 = 8
⇒ (x – 1)2 – 3y2 = 9
Here, center of the hyperbola is (1, 0)
Let x – 1 = X
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (±ae, 0)
Equation of directrix are:
Length of latus rectum is
Here, a = 3 and b =
Therefore,
⇒ and y = 0
⇒ and y = 0
⇒ and y = 0
Equation of directrix are:
Find the equation of the hyperbola, referred to its principal axes as axes of coordinates, in the following cases:
the distance between the foci = 16 and eccentricity =
Given: the distance between the foci = 16 and eccentricity
To find: the equation of the hyperbola
Formula used:
For hyperbola:
Distance between the foci is 2ae and b2 = a2(e2 – 1)
Therefore
2ae = 16
b2 = a2(e2 – 1)
Equation of hyperbola is:
Hence, required equation of hyperbola is x2 – y2 = 32
Find the equation of the hyperbola, referred to its principal axes as axes of coordinates, in the following cases:
conjugate axis is 5 and the distance between foci = 13
Given: the distance between the foci = 13 and conjugate axis is 5
To find: the equation of the hyperbola
Formula used:
For hyperbola:
Distance between the foci is 2ae and b2 = a2(e2 – 1)
Length of conjugate axis is 2b
Therefore
2ae = 13
b2 = a2(e2 – 1)
⇒ b2 = a2e2 – a2
Equation of hyperbola is:
Hence, required equation of hyperbola is 25x2 – 144y2 = 900
Find the equation of the hyperbola, referred to its principal axes as axes of coordinates, in the following cases:
conjugate axis is 7 and passes through the point (3, -2).
Given: conjugate axis is 5 and passes through the point (3, -2)
To find: the equation of the hyperbola
Formula used:
For hyperbola:
Conjugate axis is 2b
Therefore
The equation of hyperbola is:
Since it passes through (3, -2)
The equation of hyperbola:
Hence, required equation of hyperbola is 65x2 – 36y2 = 441
Find the equation of the hyperbola whose
foci are (6, 4) and (-4, 4) and eccentricity is 2.
Given: Foci are (6, 4) and (-4, 4) and eccentricity is 2
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two foci.
Distance between the foci is 2ae and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Center of hyperbola having foci (6, 4) and (-4, 4) is given by
= (1, 4)
The distance between the foci is 2ae, and Foci are (6, 4) and (-4, 4)
{∵ e = 2}
b2 = a2(e2 – 1)
The equation of hyperbola:
⇒ 12(x2 + 1 – 2x) – 4(y2 + 16 – 8y) = 75
⇒ 12x2 + 12 – 24x – 4y2 – 64 + 32y – 75 = 0
⇒ 12x2 – 4y2 – 24x + 32y – 127 = 0
Hence, required equation of hyperbola is 12x2 – 4y2 – 24x + 32y – 127 = 0
Find the equation of the hyperbola whose
vertices are (-8, -1) and (16, -1) and focus is (17, -1)
Given: Vertices are (-8, -1) and (16, -1) and focus is (17, -1)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two vertices
The distance between two vertices is 2a
The distance between the foci and vertex is ae – a and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Center of hyperbola having vertices (-8, -1) and (16, -1) is given by
= (4, -1)
The distance between two vertices is 2a and vertices are (-8, -1) and (16, -1)
The distance between the foci and vertex is ae – a, Foci is (17, -1) and the vertex is (16, -1)
b2 = a2(e2 – 1)
The equation of hyperbola:
⇒ 25(x2 + 16 – 8x) – 144(y2 + 1 + 2y) = 3600
⇒ 25x2 + 400 – 200x – 144y2 – 144 – 288y – 3600 = 0
⇒ 25x2 – 144y2 – 200x – 288y – 3344 = 0
Hence, required equation of hyperbola is 25x2 – 144y2 – 200x – 288y – 3344 = 0
Find the equation of the hyperbola whose
foci are (4, 2) and (8, 2) and eccentricity is 2.
Given: Foci are (4, 2) and (8, 2) and eccentricity is 2
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two foci.
Distance between the foci is 2ae and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Center of hyperbola having foci (4, 2) and (8, 2) is given by
= (6, 2)
The distance between the foci is 2ae and Foci are (4, 2) and (8, 2)
{∵ e = 2}
b2 = a2(e2 – 1)
The equation of hyperbola:
⇒ 3(x2 + 36 – 12x) – (y2 + 4 – 4y) = 3
⇒ 3x2 + 108 – 36x – y2 – 4 + 4y – 3 = 0
⇒ 3x2 – y2 – 36x + 4y + 101 = 0
Hence, required equation of hyperbola is 3x2 – y2 – 36x + 4y + 101 = 0
Find the equation of the hyperbola whose
vertices are at (0. ± 7) and foci at
Given: Vertices are (0, ± 7) and foci are
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Vertices of the hyperbola are given by (0, ±b)
Foci of the hyperbola are given by (0, ±be)
Vertices are (0, ±7) and foci are
Therefore,
a2 = b2(e2 – 1)
The equation of hyperbola:
⇒ 9x2 – 7y2 = -343
⇒ 9x2 – 7y2 + 343 = 0
Hence, required equation of hyperbola is 9x2 – 7y2 + 343 = 0
Find the equation of the hyperbola whose
vertices are at (±6, 0) and one of the directrices is x = 4.
Given: Vertices are (± 6, 0) and one of the directrices is x = 4
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Vertices of the hyperbola are given by (±a, 0)
The equation of the directrices:
Vertices are (± 6, 0) and one of the directrices is x = 4
Therefore,
b2 = a2(e2 – 1)
⇒ b2 = 45
The equation of hyperbola:
⇒ 5x2 – 4y2 = 180
⇒ 5x2 – 4y2 – 180 = 0
Hence, required equation of hyperbola is 5x2 – 4y2 – 180 = 0
Find the equation of the hyperbola whose
foci at (± 2, 0) and eccentricity is 3/2.
Given: Foci are (2, 0) and (-2, 0) and eccentricity is
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two foci.
Distance between the foci is 2ae and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Center of hyperbola having Foci (2, 0) and (-2, 0) is given by
= (0, 0)
The distance between the foci is 2ae, and Foci are (2, 0) and (-2, 0)
b2 = a2(e2 – 1)
The equation of hyperbola:
⇒ 45x2 – 36y2 – 80 = 0
Hence, required equation of hyperbola is 45x2 – 36y2 – 80 = 0
Find the eccentricity of the hyperbola, the length of whose conjugate axis is of the length of the transverse axis.
Given: the length of whose conjugate axis is of the length of the transverse axis
To find: eccentricity of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Length of the conjugate axis is 2b and length of transverse axis is 2a
According to question:
We know,
Hence, the eccentricity of the hyperbola is
Find the equation of the hyperbola whose
the focus is at (5, 2), vertices at (4, 2) and (2, 2) and centre at (3, 2)
Given: Vertices are (4, 2) and (2, 2), the focus is (5, 2) and centre (3, 2)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two vertices
The distance between two vertices is 2a
The distance between the foci and vertex is ae – a and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
The distance between two vertices is 2a and vertices are (4, 2) and (2, 2)
The distance between the foci and vertex is ae – a, Foci is (5, 2) and the vertex is (4, 2)
⇒ 1 = e – 1
⇒ e = 1 + 1
⇒ e = 2
b2 = a2(e2 – 1)
The equation of hyperbola:
{∵ Centre (3, 2)}
⇒ 3(x2 + 9 – 6x) – (y2 + 4 – 4y) = 3
⇒ 3x2 + 27 – 18x – y2 – 4 + 4y – 3 = 0
⇒ 3x2 – y2 – 18x + 4y + 20 = 0
Hence, required equation of hyperbola is 3x2 – y2 – 18x + 4y + 20 = 0
Find the equation of the hyperbola whose
focus is at (4, 2), centre at (6, 2) and e = 2.
Given: Foci is (4, 2), e = 2 and center at (6, 2)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Center is the mid-point of two vertices
The distance between two vertices is 2a
The distance between the foci and vertex is ae – a and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Therefore
Let one of the two foci is (m, n) and the other one is (4, 2)
Since, Centre(6, 2)
Foci are (4, 2) and (8, 2)
The distance between the foci is 2ae and Foci are (4, 2) and (8, 2)
⇒ a2 = 1
b2 = a2(e2 – 1)
⇒ b2 = 4 – 1
⇒ b2 = 3
The equation of hyperbola:
⇒ 3(x2 + 36 – 12x) – (y2 + 4 – 4y) = 3
⇒ 3x2 + 108 – 36x – y2 – 4 + 4y – 3 = 0
⇒ 3x2 – y2 – 36x + 4y + 101 = 0
Hence, required equation of hyperbola is 3x2 – y2 – 36x + 4y + 101 = 0
If P is any point on the hyperbola whose axis are equal, prove that SP.S’P = CP2
Given: Axis of the hyperbola are equal, i.e. a = b
To prove: SP.S’P = CP2
Formula used:
The standard form of the equation of the hyperbola is,
Foci of the hyperbola are given by (±ae, 0)
Let P (m, n) be any point on the hyperbola
The distancebetween two points (m, n) and (a, b) is given by
C is Centre with coordinates (0, 0)
Now,
{∵ a2 = m2 – n2}
From (i):
Taking square root both sides:
Hence Proved
In each of the following find the equations of the hyperbola satisfying the given conditions
vertices (± 2, 0), foci (± 3, 0)
Given: Vertices are (±2, 0) and foci are (±3, 0)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Vertices of the hyperbola are given by (±a, 0)
Foci of the hyperbola are given by (±ae, 0)
Vertices are (±2, 0) and foci are (±3, 0)
Therefore,
a = 2 and ae = 3
⇒ 2 × e = 3
b2 = a2(e2 – 1)
⇒ b2 = 5
The equation of hyperbola:
⇒ 5x2 – 4y2 = 20
⇒ 5x2 – 4y2 – 20 = 0
Hence, required equation of hyperbola is 5x2 – 4y2 – 20 = 0
In each of the following find the equations of the hyperbola satisfying the given conditions
vertices (0, ± 5), foci (0, ± 8)
Given: Vertices are (0, ±5) and foci are (0, ±8)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Vertices of the hyperbola are given by (0, ±b)
Foci of the hyperbola are given by (0, ±be)
Vertices are (0, ±5) and foci are (0, ±8)
Therefore,
a2 = b2(e2 – 1)
⇒ a2 = 39
The equation of hyperbola:
Hence, the required equation of the hyperbola is
In each of the following find the equations of the hyperbola satisfying the given conditions
vertices (0, ± 3), foci (0, ± 5)
Given: Vertices are (0, ±3) and foci are (0, ±5)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Vertices of the hyperbola are given by (0, ±b)
Foci of the hyperbola are given by (0, ±be)
Vertices are (0, ±3) and foci are (0, ±5)
Therefore,
a2 = b2(e2 – 1)
⇒ a2 = 16
The equation of hyperbola:
Hence, the required equation of the hyperbola is
In each of the following find the equations of the hyperbola satisfying the given conditions
foci (±5, 0), transverse axis = 8
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Length of transverse axis is 2a
Coordinates of the foci for a standard hyperbola is given by (±ae, 0)
According to question:
2a = 8 and ae = 5
2a = 8
⇒ a = 4
⇒ a2 = 16
ae = 5
We know,
b2 = a2(e2 – 1)
⇒ b2 = 4(21)
⇒ b2 = 84
Hence, the equation of the hyperbola is:
In each of the following find the equations of the hyperbola satisfying the given conditions
foci (0, ±13), conjugate axis = 24
Given: foci (0, ±13) and the conjugate axis is 24
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Length of the conjugate axis is 2b
Coordinates of the foci for a standard hyperbola is given by (0, ±be)
According to question:
2b = 24 and be = 13
2b = 24
⇒ b = 12
⇒ b2 = 144
be = 12
We know,
a2 = b2(e2 – 1)
⇒ b2 = 25
Hence, the equation of the hyperbola is:
In each of the following find the equations of the hyperbola satisfying the given conditions
foci , the latus-rectum = 8
Given: Foci and the latus-rectum = 8
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Coordinates of the foci for a standard hyperbola is given by (±ae, 0)
Length of latus rectum is
According to the question:
We know,
b2 = a2(e2 – 1)
⇒ 4a = 45 – a2
⇒ a2 + 4a – 45 = 0
⇒ a2 + 9a – 5a – 45 = 0
⇒ a(a + 9) – 5(a + 9) = 0
⇒ (a + 9)(a – 5) = 0
⇒ a = -9 or a = 5
Since a is a distance, and it can’t be negative
⇒ a = 5
⇒ a2 = 25
b2 = 4a
⇒ b2 = 4(5)
⇒ b2 = 20
Hence, equation of hyperbola is:
In each of the following find the equations of the hyperbola satisfying the given conditions
foci (±4, 0), the latus-rectum = 12
Given: Foci (±4, 0), the latus-rectum = 12
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Coordinates of the foci for a standard hyperbola is given by (±ae, 0)
Length of latus rectum is
According to the question:
ae = 4
We know,
b2 = a2(e2 – 1)
⇒ 6a = 16 – a2
⇒ a2 + 6a – 16 = 0
⇒ a2 + 8a – 2a – 16 = 0
⇒ a(a + 8) – 2(a + 8) = 0
⇒ (a + 8)(a – 2) = 0
⇒ a = -8 or a = 2
Since a is a distance, and it can’t be negative,
⇒ a = 2
⇒ a2 = 4
b2 = 6a
⇒ b2 = 6(2)
⇒ b2 = 12
Hence, equation of hyperbola is:
In each of the following find the equations of the hyperbola satisfying the given conditions
foci , passing through (2, 3)
Given: passing through (2, 3)
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Coordinates of the foci for a standard hyperbola is given by (0, ±be)
According to the question:
⇒ b2e2 = 10
Since (2, 3) passing through hyperbola
Therefore,
{∵ a2 = b2(e2 – 1)}
⇒ 90 – 13b2 = (10 – b2)b2
⇒ 90 – 13b2 = 10b2 – b4
⇒ 90 – 13b2 – 10b2 + b4 = 0
⇒ b4 – 23b2 + 90 = 0
⇒ b4 – 18b2 – 5b2 + 90 = 0
⇒ b2(b2 – 18) – 5(b2 – 18) = 0
⇒ (b2 – 18)(b2 – 5) = 0
⇒ b2 = 18 or 5
Case 1: b2 = 18 and b2e2 = 10
a2 = b2(e2 – 1)
⇒ a2 = b2e2 – b2
⇒ a2 = 10 – 18
⇒ a2 = – 8
Hence, equation of hyperbola is:
Case 2: b2 = 5 and b2e2 = 10
a2 = b2(e2 – 1)
⇒ a2 = b2e2 – b2
⇒ a2 = 10 – 5
⇒ a2 = 5
Hence, equation of hyperbola is:
In each of the following find the equations of the hyperbola satisfying the given conditions
foci (0, ± 12), latus-rectum = 36.
Given: Foci (0, ±12), the latus-rectum = 36
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
Coordinates of the foci for a standard hyperbola is given by (0, ±be)
Length of latus rectum is
According to the question:
be = 12
We know,
a2 = b2(e2 – 1)
⇒ 18b = 144 – b2
⇒ b2 + 18b – 144 = 0
⇒ b2 + 24b – 6b – 144 = 0
⇒ b(b + 24) – 6(b + 24) = 0
⇒ (b + 24)(b – 6) = 0
⇒ b = -24 or b = 6
Since b is a distance, and it can’t be negative
⇒ b = 6
⇒ b2 = 36
a2 = 18b
⇒ a2 = 18(6)
⇒ b2 = 108
Hence, equation of hyperbola is:
If the distance between the foci of a hyperbola is 16 and its eccentricity is, then obtain its equation.
Given: Distance between foci is 16 and eccentricity is
To find: equation of the hyperbola
Formula used:
The standard form of the equation of the hyperbola is,
The distance between foci is given by 2ae
According to question:
2ae = 16
⇒ a2 = 32
We know,
b2 = a2(e2 – 1)
⇒ b2 = 32
Hence, the equation of the hyperbola is:
⇒ x2 – y2 = 32
Show that the set of all points such that the difference of their distances from (4, 0) and (-4, 0) is always equal to 2 represents a hyperbola.
To prove: the set of all points under given conditions represents a hyperbola
Let a point P be (x, y) such that the difference of their distances from (4, 0) and (-4, 0) is always equal to 2.
Formula used:
The distance between two points (m, n) and (a, b) is given by
The distance of P(x, y) from (4, 0) is
The distance of P(x, y) from (-4, 0) is
Since, the difference of their distances from (4, 0) and (-4, 0) is always equal to 2
Therefore,
Squaring both sides:
Squaring both sides:
⇒ 16x2 + 1 – 8x = (x – 4)2 + y2
⇒ 16x2 + 1 – 8x = x2 + 16 – 8x + y2
⇒ 16x2 + 1 – 8x – x2 – 16 + 8x – y2 = 0
⇒ 15x2 – y2 – 15 = 0
Hence, required equation of hyperbola is 15x2 – y2 – 15 = 0
Write the eccentricity of the hyperbola 9x2 – 16y2 = 144.
Given: 9x2 – 16y2 = 144
To find: eccentricity(e)
9x2 – 16y2 = 144
Formula used:
For hyperbola
Eccentricity(e) is given by,
Here, a = 4 and b = 3
⇒ c = 5
Therefore,
Hence, eccentricity is
Write the eccentricity of the hyperbola whose latus-rectum is half of its transverse axis.
Given: Latus-rectum is half of its transverse axis
To find: eccentricity of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Length of transverse axis is 2a
Latus-rectum of the hyperbola is
According to question:
Latus-rectum is half of its transverse axis
We know,
Hence, eccentricity is
Write the coordinates of the foci of the hyperbola 9x2 – 16y2 = 144.
Given: 9x2 – 16y2 = 144
To find: coordinates of the foci f(m,n)
9x2 – 16y2 = 144
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (±ae, 0)
Here, a = 4 and b = 3
⇒ c = 5
Therefore,
Foci: (±5, 0)
Write the equation of the hyperbola of eccentricity, if it is known that the distance between its foci is 16.
Given: Distance between foci is 16 and eccentricity is
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Distance between foci is given by 2ae
According to question:
2ae = 16
⇒ a2 = 32
We know,
b2 = a2(e2 – 1)
⇒ b2 = 32
Hence, equation of hyperbola is:
⇒ x2 – y2 = 32
If the foci of the ellipse and the hyperbola coincide, write the value of b2
To find: value of b2
Given: foci of given ellipse and hyperbola coincide
Formula used:
Coordinates of the foci for standard ellipse is given by (±c1, 0) where
Coordinates of the foci for standard hyperbola is given by (±c2, 0) where
Since, their foci coincide
Here a1 = 4, b1 = b,
⇒ b2 = 16 – 9
⇒ b2 = 7
Write the length of the latus-rectum of the hyperbola 16x2 – 9y2 = 144.
Given: 16x2 – 9y2 = 144
To find: length of latus-rectum of hyperbola.
16x2 – 9y2 = 144
Formula used:
For hyperbola
Length of latus rectum is
Here, a = 3 and b = 4
Length of latus rectum,
If the latus-rectum through one focus of a hyperbola subtends a right angle at the farther vertex, then write the eccentricity of the hyperbola.
Given: latus-rectum through one focus of a hyperbola subtends a right angle at the farther vertex
To find: eccentricity of hyperbola
Let B is vertex of hyperbola and A and C are point of intersection of latus-rectum and hyperbola
Standard equation of hyperbola is
Since, A and C lie on hyperbola
Therefore
As angle between AB and AC is 90°
⇒ SlopeAB × SlopeBC = -1
From (i):
{∵ b2 = a2(e2 – 1)}
⇒ (e2 – 1)2 = (e + 1)2
⇒ e4 + 1 – 2e2 = e2 + 1 + 2e
⇒ e4 + 1 – 2e2 – e2 – 1 – 2e = 0
⇒ e4 – 3e2 – 2e = 0
⇒ e(e3 – 3e – 2) = 0
⇒ e(e– 2)(e + 1)2 = 0
⇒ e = 0 or 2 or -1
But e should be greater than or equal to 1 for hyperbola
⇒ e = 2
Hence, eccentricity of hyperbola is 2
Write the distance between the directrices of the hyperbola
x = 8 sec θ, y = 8 tan θ.
Given: Hyperbola is x = 8 sec θ and y = 8 tan θ
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Distance between directrix is given by
x = 8 sec θ and y = 8 tan θ
We know,
sec2 θ – tan2 θ = 1
Here a = 8 and b = 8
Now,
Hence, distance between directrix,
Write the equation of the hyperbola whose vertices are (±3, 0) and foci at (±5, 0).
Given: Vertices are (±3, 0) and foci are (±5, 0)
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Vertices of hyperbola are given by (±a, 0)
Foci of hyperbola are given by (±ae, 0)
Vertices are (±3, 0) and foci are (±5, 0)
Therefore,
a = 3 and ae = 5
⇒ 3 × e = 5
b2 = a2(e2 – 1)
⇒ b2 = 16
Equation of hyperbola:
Hence, required equation of hyperbola is
If e1 and e2 are respectively the eccentricities of the ellipse and the hyperbola , then write the value of 2e12 + e22.
Given: e1 and e2 are respectively the eccentricities of the ellipse and the hyperbola
To find: value of 2e12 + e22
Eccentricity(e) of hyperbola is given by,
Here a = 3 and b = 2
Therefore,
For ellipse:
Eccentricity(e) of ellipse is given by,
Therefore,
Substituting values from (1) and (2) in 2e12 + e22
2e12 + e22
= 3
Hence, value of 2e12 + e22 is 3
Equation of the hyperbola whose vertices are (± 3, 0) and foci at (± 5, 0), is
A. 16x2 – 9y2 = 144
B. 9x2 – 16y2 = 144
C. 25x2 – 9y2 = 225
D. 9x2 – 25y2 = 81
Given: Vertices are (±3, 0) and foci are (±5, 0)
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Vertices of hyperbola are given by (±a, 0)
Foci of hyperbola are given by (±ae, 0)
Vertices are (±3, 0) and foci are (±5, 0)
Therefore,
a = 3 and ae = 5
⇒ 3 × e = 5
b2 = a2(e2 – 1)
⇒ b2 = 16
Equation of hyperbola:
⇒ 16x2 – 9y2 = 144
Hence, required equation of hyperbola is 16x2 – 9y2 = 144
If e1 and e2 are respectively the eccentricities of the ellipse and the hyperbola , then the relation between e1 and e2 is
A. 3e12 + e22 = 2
B. e12 + 2e22 = 3
C. 2e12 + e22 = 3
D. e12 + 3e22 = 2
Given: e1 and e2 are respectively the eccentricities of the ellipse and the hyperbola
To find: value of 2e12 + e22
Eccentricity(e) of hyperbola is given by,
Here a = 3 and b = 2
Therefore,
For ellipse:
Eccentricity(e) of ellipse is given by,
Therefore,
Substituting values from (1) and (2) in 2e12 + e22
2e12 + e22
= 3
Hence, value of 2e12 + e22 is 3
The distance between the directrices of the hyperbola x = 8 sec θ, y = 8 tan θ, is
A.
B.
C.
D.
Given: Hyperbola is x = 8 sec θ and y = 8 tan θ
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Distance between directrix is given by
x = 8 sec θ and y = 8 tan θ
We know,
sec2 θ – tan2 θ = 1
Here a = 8 and b = 8
Now,
Hence, distance between directrix,
The equation of the conic with focus at (1, -1) directrix along x – y + 1= 0 and eccentricity is
A. xy = 1
B. 2xy + 4x – 4y – 1 = 0
C. x2 – y2 = 1
D. 2xy – 4x + 4y + 1 = 0
Given: Equation of directrix of a hyperbola is x – y + 1= 0. Focus of hyperbola is (1, -1) and eccentricity (e) is
To find: equation of conic
Let M be the point on directrix and P(x, y) be any point of hyperbola
Formula used:
where e is eccentricity, PM is perpendicular from any point P on hyperbola to the directrix
Therefore,
Squaring both sides:
{∵ (a – b)2 = a2 + b2 + 2ab}
⇒ x2 + 1 – 2x + y2 + 1 + 2y = x2 + y2 + 1 – 2xy + 2x – 2y
⇒ x2 + 1 – 2x + y2 + 1 + 2y – x2 – y2 + 2xy – 1 – 2x + 2y = 0
⇒ 2xy – 4x + 4y + 1 = 0
This is the required equation of hyperbola
The eccentricity of the conic 9x2 – 16y2 = 144 is
A.
B.
C.
D.
Given: 9x2 – 16y2 = 144
To find: eccentricity(e)
9x2 – 16y2 = 144
Formula used:
For hyperbola
Eccentricity(e) is given by,
Here, a = 4 and b = 3
⇒ c = 5
Therefore,
Hence, eccentricity is
The latus-rectum of the hyperbola 16x2 – 9y2 = 144 is
A. 16/3
B. 32/3
C. 8/3
D. 4/3
Given: 16x2 – 9y2 = 144
To find: length of latus-rectum of hyperbola.
16x2 – 9y2 = 144
Formula used:
For hyperbola
Length of latus rectum is
Here, a = 3 and b = 4
Length of latus rectum,
A point moves in a plane so that its distances PA and PB from two fixed points A and B in the plane satisfy the relation PA – PB = k(k ≠ 0), then the locus of P is
A. a hyperbola
B. a branch of the hyperbola
C. a parabola
D. an ellipse
We know it by the fact that when difference in distances is constant, it forms as hyperbola
The eccentricity of the hyperbola whose latus-rectum is half of its transverse axis, is
A.
B.
C.
D. none of these
Given: Latus-rectum is half of its transverse axis
To find: eccentricity of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Length of transverse axis is 2a
Latus-rectum of the hyperbola is
According to question:
Latus-rectum is half of its transverse axis
We know,
Hence, eccentricity is
The eccentricity of the hyperbola x2 – 4y2 = 1 is
A.
B.
C.
D.
Given: x2 – 4y2 = 1
To find: eccentricity(e)
x2 – 4y2 = 1
Formula used:
For hyperbola
Eccentricity(e) is given by,
Here, a = 1 and
Therefore,
Hence, eccentricity is
The difference of the focal distances of any point on the hyperbola is equal to
A. length of the conjugate axis
B. eccentricity
C. length of the transverse axis
D. Latus-rectum
This is definition of eccentricity.
Eccentricity is difference of the focal distances of any point on the hyperbola
the foci of the hyperbola 9x2 – 16y2 = 144 are
A. (± 4, 0)
B. (0, ± 4)
C. (± 5, 0)
D. (0, ± 5)
Given: 9x2 – 16y2 = 144
To find: coordinates of the foci f(m,n)
9x2 – 16y2 = 144
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (±ae, 0)
Here, a = 4 and b = 3
⇒ c = 5
Therefore,
Foci: (±5, 0)
The distance between the foci of a hyperbola is 16 and its eccentricity is , then equation of the hyperbola is
A. x2 + y2 = 32
B. x2 – y2 = 16
C. x2 + y2 = 16
D. x2 – y2 = 32
Given: Distance between foci is 16 and eccentricity is
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Distance between foci is given by 2ae
According to question:
2ae = 16
⇒ a2 = 32
We know,
b2 = a2(e2 – 1)
⇒ b2 = 32
Hence, equation of hyperbola is:
⇒ x2 – y2 = 32
If e1 is the eccentricity of the conic 9x2 + 4y2 = 36 and e2 is the eccentricity of the conic 9x2 – 4y2 = 36, then
A. e12 – e22 = 2
B. 2 < e22 – e12< 3
C. e22 – e12 = 2
D. e22 – e12> 3
Given: e1 and e2 are respectively the eccentricities of 9x2 + 4y2 = 36 and 9x2 – 4y2 = 36 respectively
To find: e12 – e22
9x2 – 4y2 = 36
Eccentricity(e) of hyperbola is given by,
Here a = 2 and b = 3
Therefore,
For ellipse:
9x2 + 4y2 = 36
Eccentricity(e) of ellipse is given by,
Here a = 2 and b = 3
Therefore,
Substituting values from (1) and (2) in 2e12 + e22
e12 – e22
⇒ e22 – e22
Hence, value of 2 < e22 – e12 < 3
If the eccentricity of the hyperbola x2 – y2 sec2∝ = 5 is times the eccentricity of the ellipse x2 sec2∝ +y2 = 25, then ∝ =
A.
B.
C.
D.
Given: e1 and e2 are respectively the eccentricities of x2 – y2 sec2 α = 5 and x2 sec2 α + y2 = 25 respectively
To find: value of α
x2 – y2 sec2 α = 5
Eccentricity(e) of hyperbola is given by,
Therefore,
For ellipse:
x2 sec2 α + y2 = 25
Eccentricity(e) of ellipse is given by,
Therefore,
According to question:
Eccentricity of given hyperbola is time eccentricity of given ellipse
From (1) and (2):
Squaring both sides:
⇒ 1 + cos2 α = 3(1 – cos2 α)
⇒ 1 + cos2 α = 3 – 3 cos2 α
⇒ 3 cos2 α + cos2 α = 3 – 1
⇒ 4 cos2 α = 2
The equation of the hyperbola whose foci are (6, 4) and (-4, 4) and eccentricity 2, is
A.
B.
C.
D. none of these
Given: Foci are (6, 4) and (-4, 4) and eccentricity is 2
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Center is the mid-point of two foci.
Distance between the foci is 2ae and b2 = a2(e2 – 1)
Distance between two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Center of hyperbola having foci (6, 4) and (-4, 4) is given by
= (1, 4)
Distance between the foci is 2ae and Foci are (6, 4) and (-4, 4)
{∵ e = 2}
b2 = a2(e2 – 1)
Equation of hyperbola:
Hence, required equation of hyperbola is
The length of the straight line x – 3y = 1 intercepted by the hyperbola x2 – 4y2 = 1 is
A.
B.
C.
D. none of these
Given: A straight line x – 3y = 1 intercepts hyperbola x2 – 4y2 = 1
To find: Length of the intercepted line
Formula used:
Distance between two points (m, n) and (a, b) is given by
Firstly we will find point of intersections of given line and hyperbola
x – 3y = 1 ⇒ x = 1 + 3y
x2 – 4y2 = 1
⇒ (1 + 3y)2 – 4y2 = 1
⇒ 1 + 9y2 + 6y – 4y2 = 1
⇒ 5y2 + 6y = 0
⇒ y(5y + 6) = 0
⇒ y = 0 or 5y + 6 = 0
Now, x = 1 + 3y
So, Point of intersections are A(1, 0) and
Distance between point of intersections is
The foci of the hyperbola 2x2 – 3y2 = 5 are
A.
B. (± 5/6, 0)
C.
D. none of these
Given: 2x2 – 3y2 = 5
To find: coordinates of the foci f(m,n)
2x2 – 3y2 = 5
Formula used:
For hyperbola
Eccentricity(e) is given by,
Foci is given by (±ae, 0)
Therefore,
The eccentricity the hyperbola is
A.
B.
C.
D.
Given: Equation of hyperbola
To find:Eccentricity of the hyperbola
Squaring both sides:
Squaring both sides:
From (1) and (2):
Formula used:
For hyperbola
Eccentricity(e) is given by,
Here a = a, b = a
Therefore,
Hence, theeccentricity of the hyperbola is
The equation of the hyperbola whose centre is (6, 2) one focus is (4, 2) and of eccentricity 2 is
A. 3 (x – 6)2 – (y – 2)2 = 3
B. (x – 6)2 – 3 (y – 2)2 = 1
C. (x – 6)2 – 2(y – 2)2 = 1
D. 2(x – 6)2 – (y – 2)2 = 1
Given: Foci is (4, 2), e = 2 and center at (6, 2)
To find: equation of the hyperbola
Formula used:
Standard form of the equation of hyperbola is,
Center is the mid-point of two vertices
The distance between two vertices is 2a
The distance between the foci and vertex is ae – a and b2 = a2(e2 – 1)
The distancebetween two points (m, n) and (a, b) is given by
Mid-point theorem:
Mid-point of two points (m, n) and (a, b) is given by
Therefore
Let one of the two foci is (m, n) and the other one is (4, 2)
Since, Centre(6, 2)
Foci are (4, 2) and (8, 2)
The distance between the foci is 2ae and Foci are (4, 2) and (8, 2)
⇒ a2 = 1
b2 = a2(e2 – 1)
⇒ b2 = 4 – 1
⇒ b2 = 3
Equation of hyperbola:
⇒ 3(x – 6)2 – (y – 2)2 = 3
Hence, required equation of hyperbola is 3(x – 6)2 – (y – 2)2 = 3
The locus of the point of intersection of the lines and is a hyperbola of eccentricity
A. 1
B. 2
C. 3
D. 4
Given: A hyperbola is formed by the locus of the point of intersection of lines
To find: Eccentricity of the hyperbola
Multiply by λ:
Adding (1) and (2):
Now, From (1):
Squaring both sides:
From (3) and (4):
Formula used:
For hyperbola
Eccentricity(e) is given by,
⇒ c = 8
Therefore,
⇒ e = 2
Hence, eccentricity of hyperbola is 2