Question:
If $x^{3}+x^{2}-a x+b$ is divisible by $\left(x^{2}-x\right)$, write the values of $a$ and $b$.
Solution:
Equating $x^{2}-x$ to 0 to find the zeros, we will get
$x(x-1)=0$
$\Rightarrow x=0$ or $x-1=0$
$\Rightarrow x=0$ or $x=1$
Since, $x^{3}+x^{2}-a x+b$ is divisible by $x^{2}-x$
Hence, the zeros of $x^{2}-x$ will satisfy $x^{3}+x^{2}-a x+b$
$\therefore(0)^{3}+0^{2}-a(0)+b=0$
$\Rightarrow b=0$
and
$(1)^{3}+1^{2}-a(1)+0=0 \quad[\because b=0]$
$\Rightarrow a=2$