State whether the following expressions are polynomials in one variable or not. Give reasons for your answer.
i. 2x5 – x3 + x – 6
ii. 3x2 – 2x + 1
iii. y3 + 2√3
iv.
v.
vi. x3 + y3 + z6
i. 2x5 – x3 + x – 6
There is only one variable ‘x’ with whole number power. So, this is polynomial in one variable.
ii. 3x2 – 2x + 1
There is only one variable ‘x’ with whole number power. So, this is polynomial in one variable.
iii. y3 + 2√3
There is only one variable ‘y’ with whole number power. So, this is polynomial in one variable.
iv.
⇒
There is only one variable ‘x’ with whole number power. So, this is polynomial in one variable.
v. 3√ t + 2t
There is only one variable ‘t’ but in 3√t, power of t is which is not a whole number. So, this is not a polynomial in one variable.
vi. x3 + y3 + z3
There are three variables x, y and z, but power is whole number. So, this is not a polynomial in one variable.
Write the coefficient of x2 and x in each of the following
i. 2 + 3x – 4x2 + x3
ii. √3 x + 1
iii. x3 + √2 x2 + 4x – 1
iv.
i 2 + 3x – 4x2 + x3
Co-efficient of x2 = -4
Co-efficient of x = 3
ii √3x + 1
Co-efficient of x2 = 0
Co-efficient of x = √3
iii x3 + √2x2 + 4x – 1
Co-efficient of x2 = √2
Co-efficient of x = 4
iv
= x2 + 3x + 6 = 0
Co-efficient of x2 = 1
Co-efficient of x = 3
Write the degree of each of the following polynomials.
i. 4 – 3x2
ii. 5y + √2
iii. 12 – x + 4x3
iv. 5
i. 4 – 3x2
Degree of the polynomial = 2
ii. 5y + √2
Degree of the polynomial = 1
iii. 12 – x + 4x3
Degree of the polynomial = 3
iv. 5
Degree of the polynomial = 0
Classify the following polynomials based on their degree.
i. 3x2 + 2x + 1
ii. 4x3 – 1
iii. y + 3
iv. y2 – 4
v. 4x3
vi. 2x
i. 3x2 + 2x +1
Since, the highest degree of polynomial is 2
It is a quadratic polynomial.
ii. 4x3 – 1
Since, the highest degree of polynomial is 3.
It is a cubic polynomial.
iii. y + 3
Since, the highest degree of polynomial is 1
It is a linear polynomial
iv. y2 – 4
Since, the highest degree of polynomial is 2
It is a quadratic polynomial.
v. 4x3
Since, the highest degree of polynomial is 3.
It is a cubic polynomial.
vi. 2x
Since, the highest degree of polynomial is 1
It is a linear polynomial
Give one example of a binomial of degree 27 and monomial of degree 49 and trinomial of degree 36.
Binomial means having two terms. So binomial of degree 27 is x27 + y.
Monomial means having one term. So, monomial of degree is x49.
Trinomial means having three term. So, trinomial of degree is x36 + y + 2.
Find the zeros of the following polynomials.
i. p(x)= 4x – 1
ii. p(x) = 3x + 5
iii. p(x) = 2x
v. p(x) = x + 9
i. p(x) = 4x – 1
⇒
⇒
Hence, is the zero of p(x).
ii. p(x) = 3x + 5
⇒
⇒
Hence, is the zero of p(x).
iii. p(x) = 2x
p(0) = 2(0) = 0
Hence, 0 is the zero of p(x).
iv. p(x) = x + 9
p(-9) = -9 + 9 = 0
Hence, -9 is the zero of p(x).
Find the roots of the following polynomial equations.
i. x – 3 = 0
ii. 5x – 6 = 0
iii. 11x + 1 = 0
iv. −9x = 0
i. x – 5 = 0
⇒ x = 5
∴ x = 5 is a root of x – 5 = 0
ii. 5x – 6 = 0
⇒ 5x = 6
⇒
∴ is a root of 5x – 6 = 0
iii. 11x + 1 = 0
⇒ 11x = -1
⇒
∴ is a root of 11x + 1 = 0.
iv. -9x = 0
⇒
⇒ x = 0
∴ x = 0 is a root of -9x = 0.
Verify Whether the following are roots of the polynomial equations indicated against them.
x2 – 5x + 6 = 0; x = 2, 3
x2 – 5x + 6 = 0
p(2) = (2)2 – 5(2) + 6
= 4 – 10 + 6
= 10 – 10 = 0
∴ x = 2 is a root of x2 – 5x + 6 = 0
p(x) = x2 – 5x + 6
p(3) = (3)2 – 5(3) + 6
= 9 – 15 + 6
= 15 – 15 = 0
∴ x = 3 is a root of x2 – 5x + 6 = 0
Verify Whether the following are roots of the polynomial equations indicated against them.
x2 + 4x + 3 = 0; x = −1, 2
x2 + 4x + 3 = 0
let p(x) = x2 + 4x + 3
p(-1) = (-1)2 + 4(-1) + 3
= 1 – 4 + 3
= 4 – 4 = 0
∴ x = -1 is a root of x2 + 4x + 3 = 0
p(x) = x2 + 4x + 3 = 0
p(2) = (2)2 + 4(2) + 3
= 4 + 8 + 3
= 11 + 4 = 15 ≠ 0
∴ x = 2 is not a root of x2 + 4x + 3 = 0.
Verify Whether the following are roots of the polynomial equations indicated against them.
x3 – 2x2 – 5x + 6 = 0; x = 1, −2, 3
x3 – 2x2 – 5x + 6 = 0
let p(x) = x3 – 2x2 – 5x + 6
p(1) = (1)3 – 2(1)2 – 5(1) + 6
= 1 – 2 × 1 – 5 + 6
= 1 – 2 – 5 + 6
= 7 – 7 = 0
∴ x = 1 is a root of x3 – 2x2 – 5x + 6 = 0.
p(x) = x3 – 2x2 – 5x + 6
p(-2) = (-2)3 – 2(-2)2 – 5(-2) + 6
= -8 – 2 × 4 – 5 × 2 + 6
= -8 – 8 + 10 + 6
= -16 + 16 = 0
∴ x = -2 is a root of x3 – 2x2 – 5x + 6 = 0.
p(x) = x3 – 2x2 – 5x + 6 = 0
p(3) = (3)3 – 2(3)2 – 5(3) + 6
= 27 – 2 × 9 – 5 × 3 + 6
= 27 – 18 – 15 + 6
= 33 – 33 = 0
∴ x = 3 is a root of x3 – 2x2 – 5x + 6 = 0.
Verify Whether the following are roots of the polynomial equations indicated against them.
x3 – 2x2 – x + 2 = 0; x = −1, 2, 3
x3 – 2x2 – x + 2 = 0
p(x) = x3 – 2x2 – x + 2 = 0
p(-1) = (-1)3 – 2(-1)2 - (-1) + 2
= -1 – 2 × 1 + 1 + 2
= -1 – 2 + 1 + 2
= -3 + 3 = 0
∴ x = -1 is a root of x3 – 2x2 – x + 2 = 0
p(x) = x3 – 2x2 – x + 2 = 0
p(2) = (2)3 – 2(2)2 – (2) + 2
= 8 – 2 × 4 – 2 + 2
= 8 – 8 – 2 + 2
= 10 – 10 = 0
∴ x = 2 is a root of x3 – 2x2 – x + 2 = 0.
p(x) = x3 – 2x2 – x + 2 = 0
p(3) = (3)3 – 2(3)2 – (3) + 2
= 27 – 2 × 9 – 3 + 2
= 27 – 18 – 3 + 2
= 29 – 21 = 8 ≠ 0
∴ x = 3 is not a root of x3 – 2x2 – x + 2 = 0.
Find the quotient the and remainder of the following division.
(5x3 – 8x2 + 5x – 7) ÷ (x – 1)
(5x3 – 8x2 + 5x – 7) ÷ (x – 1)
We see that the equation is already arranged in descending order.
Now we need to divide (5x3 – 8x2 + 5x – 7) by (x – 1).
Now we need to find out by how much should we multiple “x” to get a value as much as 5x3.
To get x3, we need to multiply x×x2.
Therefore, we need to multiply with 5x2 × (x – 1) and we get (5x3 – 5x2) now subtract (5x3 – 5x2) from 5x3 – 8x2 + 5x – 7 so we get – 3x2.
Now we carry 5x – 7 along with – 3x2, as shown below
So, in same way we have keep dividing till we get rid of x as shown below.
here (x – 1) × (– 3x)
= – 3x2 + 3x
here (x – 1) × 2
= 2x – 2
Therefore, we got the quotient = 5x2 – 3x + 2 and
Remainder = –5
Find the quotient the and remainder of the following division.
(2x2 – 3x – 14) ÷ (x + 2)
(2x2 – 3x – 14) ÷ (x + 2)
We see that the equation is already arranged in descending order.
Now we need to divide (2x2 – 3x – 14) by (x + 2).
Now we need to find out by how much should we multiple “x” to get a value as much as 2x2.
To get x2, we need to multiply x×x.
Therefore, we need to multiply with 2x × (x + 2) and we get (2x2 + 4x) now subtract (2x2 + 4x) from 2x2 – 3x – 14 so we get –7x.
Now we carry 14 along with –7x, as shown below
So, in same way we have keep dividing till we get rid of x as shown below.
here (x + 2) × (– 7)
= – 7x – 14
Therefore, we got the quotient = 2x – 7 and
Remainder = 0
Find the quotient the and remainder of the following division.
(9 + 4x + 5x2 + 3x3) ÷ (x+ 1)
(9 + 4x + 5x2 + 3x3) ÷ (x + 1)
We see that the equation is not arranged in descending order, so we need first arrange it in descending order of the power of x.
Therefore it becomes,
(3x3 + 5x2 + 4x + 9) ÷ (x + 1)
Now we need to divide (3x3 + 5x2 + 4x + 9) by (x + 1).
Now we need to find out by how much should we multiple “x” to get a value as much as 3x3.
To get x3, we need to multiply x×x2.
Therefore, we need to multiply with 3x2 × (x + 1) and we get (3x3 + 3x2) now subtract (3x3 + 3x2) from 3x3 + 5x2 + 4x + 9 so we get 2x2.
Now we carry 4x + 9 along with 2x2, as shown below
So, in same way we have keep dividing till we get rid of x as shown below.
here (x + 1) × ( 2x)
= 2x2 + 2x
here (x + 1) × 2
= 2x + 2
Therefore, we got the quotient = 3x2 + 2x + 2 and
Remainder = 7
Find the quotient the and remainder of the following division.
(4x3 – 2x2 + 6x + 7) ÷ (3 + 2x)
(4x3 – 2x2 + 6x + 7) ÷ (3 + 2x)
We see that the equation is not arranged in descending order, so we need first arrange it in descending order of the power of x.
Therefore it becomes,
(4x3 – 2x2 + 6x + 7) ÷ (2x + 3)
Now we need to divide (4x3 – 2x2 + 6x + 7) by (2x + 3)
Now we need to find out by how much should we multiple “x” to get a value as much as 4x3.
To get x3, we need to multiply x×x2.
Therefore we need to multiply with 2x2 × (2x + 3) and we get (4x3 + 6x2) now subtract (4x3 + 6x2) from 4x3 – 2x2 + 6x + 7so we get – 8x2.
Now we carry 6x + 7along with 4x2, as shown below
So, in same way we have keep dividing till we get rid of x as shown below.
here (2x + 3) × (–4x)
= – 8x2 – 12x
here (2x + 3) × 9
= 18x + 27
Therefore, we got the quotient = 2x2 – 4x + 9 and
Remainder = –20
Find the quotient the and remainder of the following division.
(−18 – 9x + 7x2) ÷ (x – 2)
(−18 – 9x + 7x2) ÷ (x – 2)
We see that the equation is not arranged in descending order, so we need first arrange it in descending order of the power of x.
Therefore it becomes,
(7x2 – 9x – 18) ÷ (x – 2)
Now we need to divide (7x2 – 9x – 18) by (x – 2).
Now we need to find out by how much should we multiple “x” to get a value as much as 7x2.
To get x2, we need to multiply x×x.
Therefore, we need to multiply with 7x × (x – 2) and we get (7x2 – 14x) now subtract (7x2 – 14x) from 7x2 – 9x – 18 so we get 5x.
Now we carry 18 along with 5x, as shown below
So, in same way we have keep dividing till we get rid of x as shown below.
here (x – 2) × 5
= 5x – 10
Therefore, we got the quotient = 7x + 5 and
Remainder = – 8
Find the remainder using remainder theorem, when
3x3 + 4x2 – 5x + 8 is divided by x – 1
3x3 + 4x2 – 5x + 8 is divided by x – 1
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 3x3 + 4x2 – 5x + 8 and we have (x – 1)
The zero of (x – 1) is 1
Now using Remainder theorem,
p(x) = 3x3 + 4x2 – 5x + 8 is divided by x – 1 then, p(1) is the remainder
p(1) = 3(1)3 + 4(1)2 – 5(1) + 8
= 3 + 4 – 5 + 8
= 10
Remainder = 10
Find the remainder using remainder theorem, when
5x3 + 2x2 – 6x + 12 is divided by x + 2
5x3 + 2x2 – 6x + 12 is divided by x + 2
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 5x3 + 2x2 – 6x + 12 and we have (x + 2)
The zero of (x + 2) is – 2
Now using Remainder theorem,
p(x) = 5x3 + 2x2 – 6x + 12 is divided by x + 2 then, p(–2) is the remainder
p(–2) = 5(–2)3 + 2(–2)2 – 6(–2) + 12
= 5×(–8) + 2×4 – (– 12) + 12
= – 40 + 8 + 12 + 12
= – 40 + 32
= – 8
Remainder = –8
Find the remainder using remainder theorem, when
2x3 – 4x2 + 7x + 6 is divided by x – 2
2x3 – 4x2 + 7x + 6 is divided by x – 2
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 2x3 – 4x2 + 7x + 6 and we have (x – 2)
The zero of (x – 2) is 2
Now using Remainder theorem,
p(x) = 2x3 – 4x2 + 7x + 6 is divided by x – 2 then, p(2) is the remainder
p(2) = 2(2)3 – 4(2)2 + 7(2) + 6
= 16 – 16 + 14 +6
= 20
Remainder = 20
Find the remainder using remainder theorem, when
4x3 – 3x2 + 2x – 4 is divided by x + 3
4x3 – 3x2 + 2x – 4 is divided by x + 3
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 4x3 – 3x2 + 2x – 4 and we have (x + 3)
The zero of (x + 3) is – 3
Now using Remainder theorem,
p(x) = 4x3 – 3x2 + 2x – 4 is divided by x + 3 then, p(– 3) is the remainder
p(– 3) = 4(–3)3 – 3(–3)2 + 2(–3) – 4
= – 108 – 27 – 6 – 4
= – 145
Remainder = –145
Find the remainder using remainder theorem, when
4x3 – 12x2 + 11x – 5 is divided by 2x – 1
4x3 – 12x2 + 11x – 5 is divided by 2x – 1
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 4x3 – 12x2 + 11x – 5 and we have (2x – 1)
The zero of (2x – 1) is
Now using Remainder theorem,
p(x) = 4x3 – 12x2 + 11x – 5 is divided by 2x – 1 then, is the remainder
Remainder = –2
Find the remainder using remainder theorem, when
8x4 + 12x3 – 2x2 – 18x + 14 is divided by x + 1
8x4 + 12x3 – 2x2 – 18x + 14 is divided by x + 1
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 8x4 + 12x3 – 2x2 – 18x + 14 and we have (x + 1)
The zero of (x + 1) is – 1
Now using Remainder theorem,
p(x) = 8x4 + 12x3 – 2x2 – 18x + 14 is divided by x + 1 then, p(– 1) is the remainder
p(– 1) = 8(–1)4 + 12(–1)3 – 2(–1)2 – 18(–1) + 14
= 8 – 12 – 2 +18 + 14
= 26
Remainder = 26
Find the remainder using remainder theorem, when
x3 – ax2 – 5x + 2a is divided by x – a
x3 – ax2 – 5x + 2a is divided by x – a
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = x3 – ax2 – 5x + 2a and we have (x – a)
The zero of (x – a) is a
Now using Remainder theorem,
p(x) = x3 – ax2 – 5x + 2a is divided by x – a then, p(a) is the remainder
p(a) = (a)3 – a(a)2 – 5(a) + 2a
= a3 – a3 – 5a+ 2a
= – 3a
Remainder = –3a
When the polynomial 2x3 – 2x2 + 9x – 8 is divided by x – 3 the remainder is 28. Find the value of a.
2x3 – ax2 + 9x – 8 is divided by x – 3 and remainder = 28
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = 2x3 – ax2 + 9x – 8 and we have (x – 3)
The zero of (x – 3) is 3
Now using Remainder theorem,
p(x) = 2x3 – ax2 + 9x – 8 is divided by x – a then, p(3) is the remainder which is 28
p(3) = 2x3 – ax2 + 9x – 8 =28
= 2(3)3 – a(3)2 + 9(3) – 8 =28
= 54 – 9a + 27 – 8 = 28
= 73 – 9a = 28
= 9a = 73 –28
= 9a = 45
a = 5
Find the value of m if x3 – 6x2 + mx + 60 leaves the remainder 2 when divided by (x + 2).
x3 – 6x2 + mx + 60 divided by (x + 2) and remainder = 2
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) = x3 – 6x2 + mx + 60 and we have (x + 2)
The zero of (x + 2) is –2
Now using Remainder theorem,
p(x) = x3 – 6x2 + mx + 60 is divided by x + 2 then, p(–2) is the remainder which is 2
p(–2) = x3 – 6x2 + mx + 60 = 2
= (–2)3 – 6(–2)2 + m(–2) + 60 =2
= – 8 – 24 – 2m + 60 = 2
= – 32 – 2m + 60 = 2
= 28 – 2m = 2
= 2m = 28 – 2
= 2m = 26
m = 13
If (x – 1) divides mx3 – 2x2 + 25x – 26 without remainder find the value of m
mx3 – 2x2 + 25x – 26 is divided by (x – 1) without remainder that means remainder = 0
Remainder theorem states that if p(x) is any polynomial and a is any real number and If p(x) is divided by the linear polynomial (x – a) , then the remainder is p(a).
Let p(x) mx3 – 2x2 + 25x – 26 and we have (x – 1)
The zero of (x – 1) is 1
Now using Remainder theorem,
p(x) = mx3 – 2x2 + 25x – 26 is divided by x – 1 then, p(1) is the remainder which is 0
p(1) = mx3 – 2x2 + 25x – 26 = 0
= m(1)3 – 2(1)2 + 25(1) – 26 = 0
= m – 2 + 25 – 26 = 0
= m – 3 = 0
m = 3
If the polynomials x3 + 3x2 – m and 2x3 – mx + 9 leaves the same remainder when they are divided by (x – 2), find the value of m. Also find the remainder
x3 + 3x2 – m and 2x3 – mx + 9 is divided by (x – 2) and the remainder is same.
Now let p(x) = x3 + 3x2 – m is divided by x – 2 then, p(2) is the remainder
p(2) = (2)3 + 3(2)2 – m
= 8 + 12 – m
= 20 – m
Now let q(x) = 2x3 – mx + 9 is divided by x – 2 then, q(2) is the remainder
q(2) = 2(2)3 – m(2) + 9
= 16 – 2m + 9
= 25 – 2m
Now, as the question says that the remainder for p(x) and q(x) is same
Therefore, p(2) = q(2)
20 – m = 25 – 2m
2m – m = 25 – 20
m = 5
Remainder = p(2) = 20 – m
= 15
Determine whether (x + 1) is a factor of the following polynomials:
6x4 + 7x3 – 5x – 4
Let f(x) = 6x4 + 7x3 – 5x – 4
By factor theorem,
x + 1 = 0 ;x = – 1
If f(– 1) = 0 then (x + 1) is a factor of f(x)
∴f(– 1) = 6(– 1)4 + 7(– 1)3 – 5(– 1) – 4
= 6 – 7 + 5 – 4 = 11 – 11 = 0
∴(x + 1) is a factor of f(x) = 6x4 + 7x3 – 5x – 4
Determine whether (x + 1) is a factor of the following polynomials:
2x4 + 9x3 + 2x2 + 10x + 15
Let f(x) = 2x4 + 9x3 + 2x2 + 10x + 15
By factor theorem,
x + 1 = 0 ;x = – 1
If f(– 1) = 0 then (x + 1) is a factor of f(x)
∴f(– 1) = 2(– 1)4 + 9(– 1)3 + 2(– 1)2 + 10(– 1) + 15
= 2 – 9 + 2 – 10 + 15 = 19 – 19 = 0
∴(x + 1) is a factor of f(x) = 2x4 + 9x3 + 2x2 + 10x + 15
Determine whether (x + 1) is a factor of the following polynomials:
3x3 + 8x2 + 6x – 5
Let f(x) = 3x3 + 8x2 + 6x – 5
By factor theorem,
x + 1 = 0 ;x = – 1
If f(– 1) = 0 then (x + 1) is a factor of f(x)
∴f(– 1) = 3(– 1)3 + 8(– 1)2 – 6(– 1) – 5
= – 3 + 8 + 6 – 5 = 6(not equal to 0)
∴(x + 1) is not a factor of f(x) = 3x3 + 8x2 + 6x – 5
Determine whether (x + 1) is a factor of the following polynomials:
x3 – 14x2 + 3x + 12
Let f(x) = x3 – 14x2 + 3x + 12
By factor theorem,
x + 1 = 0 ;x = – 1
If f(– 1) = 0 then (x + 1) is a factor of f(x)
∴f(– 1) = (– 1)3 – 14(– 1)2 + 3(– 1) + 12
= – 1 – 14 – 3 + 12 = – 6(not equal to 0)
∴(x + 1) is not a factor of f(x) = x3 – 14x2 + 3x + 12
Determine whether (x + 4) is a factor of x3 + 3x2 – 5x + 36.
Let f(x) = x3 + 3x2 – 5x + 36.
By factor theorem,
x + 4 = 0: x = – 4
If f(– 4) = 0, then (x + 4) is a factor
∴f(– 4) = (– 4)3 + 3(– 4)2 – 5(– 4) + 36
= – 64 + 48 + 20 + 36
= – 64 + 104 = 40
∴f(– 4) is not equal to 0
So, (x + 4) is not a factor of f(x).
Using factor theorem show that (x – 1) is a factor of 4x3 – 6x2 + 9x – 7.
f(x) = 4x3 – 6x2 + 9x – 7
By factor theorem,
(x – 1) = 0 ; x = 1
Since, (x – 1) is a factor of f(x)
Therefore, f(1) = 0
f(1) = 4(1)3 – 6(1)2 + 9(1) – 7 = 4 – 6 + 9 – 7 = 13 – 13 = 0
∴(x – 1) is a factor of f(x)
Determine whether (2x + 1) is a factor of 4x3 + 4x2 – x – 1.
Let f(x) = 4x3 + 4x2 – x – 1
By factor Theorem,
2x + 1 = 0 ; x = – 1/2
∴f(– 1/2) = 4(– 1/2)3 + 4(– 1/2)2 – (– 1/2) – 1
= 4(– 1/8) + 4(1/4) + (1/2) – 1
= (– 1/2) + 1 + (1/2) – 1 = 0
∴f(– 1/2) = 0
So, (2x + 1) is a factor of f(x).
Determine the value of p if (x + 3) is a factor of x3 – 3x2 – px + 24.
Let f(x) = x3 + 3x2 – px + 24.
By factor theorem,
x + 3 = 0;x = – 3
∴(x + 3) is a factor of f(x)
So, f(– 3) = 0.
f(– 3) = (– 3)3 – 3(– 3)2 – p(– 3) + 24 = 0
= >27 – 27 + 3p + 24 = 0
= > – 59 + 24 + 3p = 0
∴3p – 30 = 0
⇒ p = 30/3
⇒p = 10
The coefficient of x2 & x in 2x3 – 3x2 – 2x + 3 are respectively:
A. 2, 3
B. – 3, – 2
C. – 2, – 3
D. 2, – 3
2x3 – 3x2 – 2x + 3: Coefficient of x2 = – 3
Coefficient of x = – 2
The degree of polynomial 4x2 – 7x3 + 6x + 1 is:
A. 2
B. 1
C. 3
D. 0
Degree of polynomial = Highest power of x in the polynomial = 3
The polynomial 3x – 2 is a :
A. Linear polynomial
B. Quadratic polynomial
C. Cubic polynomial
D. constant polynomial
Given polynomial has degree = 1
The polynomial 4x2 + 2x – 2 is a :
A. Linear polynomial
B. Quadratic polynomial
C. Cubic polynomial
D. constant polynomial
Given polynomial has degree = 2
The zero of the polynomial 2x – 5:
A. 5/2
B. – 5/2
C. 2/5
D. – 2/5
Given : 2x – 5 = 0
∴ x = 5/2
So, zero of polynomial = 5/2
The root of polynomial equation 3x – 1 is:
A. – 1/3
B. 1/3
C. 1
D. 3
Given polynomial equation: 3x – 1 = 0
∴ x = 1/3
So, root = 1/3
The root of polynomial equation x2 + 2x = 0:
A. 0, 2
B. 1, 2
C. 1, – 2
D. 0, – 2
Given polynomial equation :
x2 + 2x = 0
∴x(x + 2) = 0
x = 0, x + 2 = 0
x = 0, x = – 2
So, the roots are 0 and – 2
If a polynomial p(x) is divided by (ax + b), then the remainder is:
A. p(b/a)
B. p(– b/a)
C. p(a/b)
D. p(– a/b)
f(x) = ax + b
Therefore, by Remainder Theorem, f(x) = 0
ax + b = 0
x = – b/a ∴Remainder = p(x) = p(– b/a)
If a polynomial x3 – ax2 + ax – a is divided by (x – a), then the remainder is:
A. a3
B. a2
C. a
D. – a
Given f(x) = x3 – ax2 + ax – 2
By Remainder Theorem,
x – a = 0
x = a
∴Remainder = f(a) = a3 – a3 + 2a – a = a
If (ax – b) is a factor of p(x) then,
A. p(b) = 0
B. p(– b/a) = 0
C. p(a) = 0
D. p(b/a) = 0
As (ax – b) is a factor of p(x)
ax – b = 0
∴x = b/a So, p(x) = 0 ;
p(b/a) = 0
One of the factor of x2 – 3x – 10 is :
A. x – 2
B. x + 5
C. x – 5
D. x – 3
x2 – 3x – 10 = 0
x2 – 5x + 2x – 10 = 0
x(x – 5) + 2(x – 5) = 0
(x – 5)(x + 2) = 0 Hence, (x – 5) is a factor.
One of the factor of x3 – 2x2 + 2x – 1 is :
A. x – 1
B. x + 1
C. x – 2
D. x + 2
Given: f(x) = x3 – 2x2 + 2x – 1 = 0
By hit and trial method,
put x = 1
f(1) = 1 – 2 + 2 – 1 = 0
∴(x – 1) is a factor.