Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

Let g(x) be the inverse of the function f (x) and $f'(x)=\frac{1}{1+x^3}$. Then g'(x) is equal to

Options:

$\frac{1}{1+(g(x))^3}$

$\frac{1}{1+(f(x))^3}$

$1+(g(x))^3$

$1+(f(x))^3$

Correct Answer:

$1+(g(x))^3$

Explanation:

$g(x)= f^{−1} ⇒x=f(g(x))$

$1=f'(g(x)).g'(x)$

$g'(x)=\frac{1}{f'(g(x))}=1+(g(x))^3$