Question

The derivative of ${\cos }^{-1}(2x^2-1)$ w.r.t
${\cos }^{-1}x$ is

• A. $2$
• B. $\frac{1}{2\sqrt{(1-x^2)}}$
• C. $\frac{2}{x}$
• D. $1-x^2$

Answer 1

The correct option is A $2$

${\cos }^{-1}(2x^2-1)=2{\cos }^{-1}x\therefore \frac{d\left({\cos }^{-1}\right(2x^2-1\left)\right)}{d\left({\cos }^{-1}x\right)}=2$