JEE Main202226 Jul 2022Evening ShiftMathematicsDifferentiationActual
The value of log e 2 d dx log cos x cosec x at x = π 4 is
Options
- A- 2 2
- B2 2
- C- 4
- D4
Correct answer
D. 4
Step-by-step solution
For log e 2 d d x log cos x cosec x let, y = log cos x cosec x i.e. y = - ln sin x ln cos x ⇒ d y d x = - cot x · ln cos x + tan x · ln sin x ln cos x 2 Now d y d x x = π 4 = - cot π 4 · ln cos π 4 + tan π 4 · ln sin π 4 ln cos π 4 2 = 4 ln 2 ⇒ log e 2 · 4 ln 2 = 4