Question

Find the value of $f^{-1}\left(1.5\right)$ if $f\left(x\right)=\sqrt[3]{3x^3+1}$.

• A. $3.4$
• B. $2.4$
• C. $1.3$
• D. $1.5$

Answer 1

The correct option is C $1.3$

As per the condition, $1.5=\sqrt[3]{3x^3+1}$
Taking cube roots on both the sides,
${1.5}^3=x^3+1$
$3.375-1=x^3$
$2.375=x^3$
$x\approx 1.3$