Q95 / 180 · KCET 2017 · Mathematics
The derivative of \( \cos ^{-1}\left(2 x^{2}-1\right) \) w.r.t \( \cos ^{-1} x \) is
- Correct answerA\( 12 \)
- B\( -\frac{1}{2 \sqrt{1-x^{2}}} \)
- C\( \frac{2}{x} \)
- D\( 1-x^{2} \)
Solution
Let \( y=\cos ^{-1}\left(2 x^{2} \quad 1\right)=2 \cos ^{-1} x \) and \( z=\cos ^{-1} x \)
So, \( \frac{d y}{d z}=\frac{d\left(2 \cos ^{-1} x\right)}{d \cos ^{-1} \chi}=2 \)
So, \( \frac{d y}{d z}=\frac{d\left(2 \cos ^{-1} x\right)}{d \cos ^{-1} \chi}=2 \)
Hence, the correct answer is option: 'A'.