Question

If $f:R\to R$ be mapping defined by $f\left(x\right)=x^3+5$, then $f^{-1}\left(x\right)$ is equal to

• A. ${(x+5)}^{1/3}$
• B. ${(x-5)}^{1/3}$
• C. ${(5-x)}^{1/3}$
• D. $5-x$

Answer 1

The correct option is B ${(x-5)}^{1/3}$

Let $y=f\left(x\right)=x^3+5$

$\Rightarrow$ $x={(y-5)}^{1/3}$

$\therefore$ $f^{-1}\left(x\right)={(x-5)}^{1/3}$