Question

The product of $(x^2-1)(x^4+x^2+1)$ is equal to

Answer 1

$(x^2-1)(x^4+x^2+1)$
$(x^2-1)\left[\right(x^2{)}^2+x^2\times 1+\left(1{)}^2\right]$
$\left\{\text{Using identity}\right(a^3-b^3)=(a-b\left)\right(a^2+ab+b^2\left)\right\}$
$=\left[\right(x^2{)}^3-\left(1{)}^3\right]$
$=(x^6-1)$

Hence, $\left(c\right)$ is the correct option.