If $y=\sin ^2\left(\cot ^{-1} \sqrt{\frac{1+x}{1-x}}\right)$, then $\frac{\mathrm{d} y}{\mathrm{~d} x}$ has…

If $y=\sin ^2\left(\cot ^{-1} \sqrt{\frac{1+x}{1-x}}\right)$, then $\frac{\mathrm{d} y}{\mathrm{~d} x}$ has the value
  1. $\frac{-1}{2}$
  2. $\frac{1}{2}$
  3. -1
  4. 1

Solution

$y=\sin ^2\left(\cot ^{-1} \sqrt{\frac{1+x}{1-x}}\right)$
Let $\theta=\cot ^{-1} \sqrt{\frac{1+x}{1-x}}$ $\begin{array}{ll} \therefore & \cot ^2 \theta=\frac{1+x}{1-x} \\ \therefore & 1+\cot ^2 \theta=\frac{2}{1-x} \\ \therefore & \sin ^2 \theta=\frac{1-x}{2} \\ \therefore & \theta=\sin ^{-1} \sqrt{\frac{1-x}{2}} \\ \therefore & y=\left[\sin \left(\sin ^{-1} \sqrt{\frac{1-x}{2}}\right)\right]^2 \\ \therefore & y=\frac{1-x}{2} \\ \therefore & \frac{\mathrm{~d} y}{\mathrm{~d} x}=\frac{-1}{2} \end{array}$

Asked in: MHT CET 2024 (10 May Shift 2)

Practice more Differentiation questions on Aicharya