JEE Main201912 Jan 2019Morning ShiftMathematicsDifferentiationActual
For x > 1 , if 2 x 2 y = 4 e 2 x - 2 y , then 1 + log e ⁡ 2 x 2 d y d x is equal to
Options
- Alog e 2 x
- Bx log e 2 x - log e 2 x
- Cx log e 2 x
- Dx log e 2 x + log e 2 x
Correct answer
B. x log e 2 x - log e 2 x
Step-by-step solution
Given, 2 x 2 y = 4 . e 2 x - 2 y Taking natural logarithm on both sides, we get 2 y   l o g e 2 x =   l o g e 4 + 2 x - 2 y ⇒ 2 y = l o g e 4 + 2 x 1 + l o g e 2 x Differentiating both sides with respect to x , we get 2 d y d x = 1 + log e 2 x . 2 - log e 4 + 2 x 1 x 1 + log e 2 x 2 (Using quotient rule) ⇒ 1 + log e 2 x 2 d y d x = x . l o g e 2 x - l o g e 2 x .