Differentiation Question 115

Question: Differential coefficient of $ {{\sin }^{-1}}x $ w.r.t $ {{\cos }^{-1}}\sqrt{1-x^{2}} $ is

[MNR 1983; AMU 2002]

Options:

A) 1

B) $ \frac{1}{1+x^{2}} $

C) 2

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

Let $ y_1={{\sin }^{-1}}x $ and $ y_2={{\cos }^{-1}}\sqrt{1-x^{2}} $

Differentiating w.r.t. x of $ y_1 $ and $ y_2 $ , we get $ \frac{dy_1}{dx}=\frac{1}{\sqrt{1-x^{2}}} $

$ \frac{dy_2}{dx}=-\frac{1}{\sqrt{1-(1-x^{2})}}\frac{1(-2x)}{2\sqrt{1-x}}=\frac{1}{\sqrt{1-x^{2}}}\Rightarrow \frac{dy_2}{dy_1}=1. $