Question

Verify whether the indicated numbers are zeros of the polynomials corresponding to them in the following cases:

(ii) $f\left(x\right)=x^2-1,x=1,-1$

Answer 1

Given : $f\left(x\right)=x^2-1andx=1,-1$

We know that if $f\left(a\right)=0;$ then $a$ is the zero of the polynomial $f\left(x\right)$.

$\therefore f\left(1\right)=(1{)}^2-1$

$=1-1=0$

And $f(-1)=(-1{)}^2-1$

$=1-1=0$

$\because f\left(1\right)=0andf(-1)-0$

Hence, $x=1,-1$ is the zero of $f\left(x\right)=x^2-1$, verified.