Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Inverse Trigonometric Functions

Question:

Match List I with List II

LIST I LIST II
A. $\frac{d}{dx}\left[tan^{-1}\left(\frac{3x-x^3}{1-3x^2}\right)\right]$ I. $\frac{3}{1+x^2}$
B. $\frac{d}{dx}\left[cos^{-1}\left(\frac{1-x^2}{1+x^2}\right)\right]$ II. $\frac{-3}{1+x^2}$
C. $\frac{d}{dx}\left[cos^{-1}\left(\frac{2x}{1+x^2}\right)\right]$ III. $\frac{-2}{1+x^2}$
D. $\frac{d}{dx}\left[cot^{-1}\left(\frac{3x-x^3}{1-3x^2}\right)\right]$ IV. $\frac{2}{1+x^2}$

Choose the correct answer from the options given below :

Options:

A-II, B-III, C-I, D-IV

A-IV, B-II, C-I, D-III

A-III, B-I, C-IV, D-II

A-I, B-IV, C-III, D-II

Correct Answer:

A-I, B-IV, C-III, D-II

Explanation:

The correct answer is Option (4) → A-I, B-IV, C-III, D-II

(A) $\frac{d}{dx}\left[tan^{-1}\left(\frac{3x-x^3}{1-3x^2}\right)\right]=\frac{d}{dx}(3\tan^{-1}x)=\frac{3}{1+x^2}$ (I)

(B) $\frac{d}{dx}\left[cos^{-1}\left(\frac{1-x^2}{1+x^2}\right)\right]=\frac{d}{dx}(2\tan^{-1}x)=\frac{2}{1+x^2}$ (IV)

(C) $\frac{d}{dx}\left[cos^{-1}\left(\frac{2x}{1+x^2}\right)\right]=\frac{d}{dx}\left(\frac{π}{2}-\sin^{-1}\frac{2x}{1+x^2}\right)$

$=\frac{d}{dx}\left(\frac{π}{2}-2\tan^{-1}x\right)=\frac{-2}{1+x^2}$ (III)

(D) $\frac{d}{dx}\left[cot^{-1}\left(\frac{3x-x^3}{1-3x^2}\right)\right]$

$\frac{d}{dx}\left(\frac{π}{2}-\tan^{-1}\frac{3x-x^3}{1+3x^2}\right)=\frac{d}{dx}\left(\frac{π}{2}-3\tan^{-1}x\right)=\frac{-3}{1+x^2}$ (II)