NTA Abhyas JEE Main2020MathematicsApplication of DerivativesPractice
If f x is a twice differentiable function such that f 0 = f 1 = f 2 = 0 , then
Options
- Af x = 0 has exactly 3 roots
- Bf ′ x = 0 for atleast 3 real values of x
- Cf ″ x = 0 for atleast 2 real values of x
- Df ″ x = 0 for atleast 1 real value of x
Correct answer
D. f ″ x = 0 for atleast 1 real value of x
Step-by-step solution
f x = 0 has atleast 3 real roots ∴ By Rolle’s theorem f ′ x = 0 has atleast two real roots and f '' x = 0 has atleast one real root.