Question:
Write the zeros of the polynomial $x^{2}-x-6$
Solution:
We have to find the zeros of the polynomial $x^{2}-x-6$
$f(x)=x^{2}-x-6$
$f(x)=x^{2}-3 x+2 x-6$
$f(x)=x(x-3)+2(x-3)$
$f(x)=(x+2)(x-3)$
We know that if $(x-\alpha)$ is a factor of $f(x)$ then $x=\alpha$ is a zero of polynomial
Therefore we have
$x+2=0$
$x=-2$
Also
$x-3=0$
$x=3$
Hence, the zeros of polynomial $x^{2}-x-6$ is $3,-2$