JEE Main2016MathematicsContinuity and DifferentiabilityActual
For x ∈ R , f x = log 2 - sin x and g x = f f x , then
Options
- Ag ' 0 = - cos log 2
- Bg is differentiable at x = 0 and g ' 0 = - sin log 2
- Cg is not differentiable at x = 0
- Dg ' 0 = cos log 2
Correct answer
D. g ' 0 = cos log 2
Step-by-step solution
In the neighborhood of x = 0 , f x = log 2 - sin x ∴ g x = f ( f x ) = log 2 - sin f x = log 2 - sin log 2 - sin x ∴ g ′ x = - cos log 2 - sin x – cos x ∴ g ′ 0 = cos log 2