MHT CET2016MathematicsApplication of Derivatives
If Rolle's theorem for a function f x = e x sin x - cos x is verified on π 4 , 5 π 4 then the value of c is
Options
- Aπ 3
- Bπ 2
- C3 π 4
- Dπ
Correct answer
D. π
Step-by-step solution
Given, f x = e x ( sin x - cos x ) ∴ f ′ x = e x cos x + sin x + sin x - cos x e x ∴ f ′ x = 2 e x sin x To verify Rolle's Theorem. f ′ c = 0 2 e c sin c = 0 ⇒ sin c = 0 ∴ c = π