Question

If $f:R\to R,g:R\to R$ are defined by $f\left(x\right)=x^2,g\left(x\right)=\cos x$ then $\left(gof\right)\left(x\right)=$

• A. $\cos 2x$
• B. $x^2\cos x$
• C. $\cos x^2$
• D. ${\cos }^2{x}^2$

Answer 1

The correct option is C $\cos x^2$

$gof\left(x\right)=g\left(f\left(x\right)\right)=g\left(x^2\right)$
$=\cos x^2$