For which values of $a$ and $b$ are the zeroes of $q(x) = x^{3} + 2x^{2} + a$ also the zeroes of the polynomial $p(x) = x^{5} - x^{4} - 4x^{3} + 3x^{2} + 3x + b$? Which zeroes of $p(x)$ are not the zeroes of $q(x)$?

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(A) Given that the zeroes of $q(x) = x^{3} + 2x^{2} + a$ are also the zeroes of $p(x) = x^{5} - x^{4} - 4x^{3} + 3x^{2} + 3x + b$,it implies that $q(x)$ is a factor of $p(x)$.
Performing polynomial long division of $p(x)$ by $q(x)$:
Dividing $x^{5} - x^{4} - 4x^{3} + 3x^{2} + 3x + b$ by $x^{3} + 2x^{2} + a$ yields a quotient of $x^{2} - 3x + 2$ and a remainder of $-(1+a)x^{2} + (3+3a)x + (b-2a)$.
Since $q(x)$ is a factor,the remainder must be zero for all $x$,so the coefficients must be zero:
$-(1+a) = 0 \Rightarrow a = -1$
$3+3a = 0 \Rightarrow 3+3(-1) = 0$ (Consistent)
$b-2a = 0 \Rightarrow b = 2(-1) = -2$.
Thus,$a = -1$ and $b = -2$.
Substituting these values,$p(x) = (x^{3} + 2x^{2} - 1)(x^{2} - 3x + 2)$.
Factoring the quotient: $x^{2} - 3x + 2 = (x-1)(x-2)$.
The zeroes of $p(x)$ are the zeroes of $q(x)$ along with the zeroes of the quotient,which are $x=1$ and $x=2$. Therefore,the zeroes of $p(x)$ that are not zeroes of $q(x)$ are $1$ and $2$.

Explore More

Similar Questions

The degree of $p(x) = x^2(1 + x + x^2) + 5$ is.............

Which of the following statements is true?

Divide $x^{6}+5 x^{3}+7 x+3$ by $x^{2}+2$.

The total cost of $(x+1)$ cameras is ₹ $(x^{3}+3x^{2}+5x+3)$. Find the cost of one camera.

Difficult
View Solution

Divide $3x^{2}-x^{3}-3x+5$ by $x-1-x^{2}$ and verify the division algorithm.

Difficult
View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo