Question

7 dx = rcos 2x -1 Jcos 2x +1 (A) tan x - x+c (B) x + tan x + c X – tan x + c (D) - X - cot x + c

JEE/Engineering Exams

Maths

Solution

126

4.0 (1 ratings)

( int frac{cos (2 x)-1}{cos (2 x)+1} d ) ( =int-frac{sin ^{2} x}{cos ^{2} x} d x ) ( operatorname{arct}-int frac{sin ^{2} x}{cos ^{2} x} d x ) ( =-int tan ^{2} x d x ) ( =-intleft(operatorname{suc}^{2} x-1right) d x ) ( =-int sec ^{2} x d x+int 1 d x ) ( =-tan x+x+c ) ( left[because int sec ^{2} x d x=tan xright] ) ( =x-tan x+c ) I then ( (c) )