NTA Abhyas JEE Main2020MathematicsArea Under CurvesPractice
If the maximum area bounded by y 2 = 4 x and the line y = m x ∀ m ∈ 1 , 3 is k square units, then the smallest prime number greater than 3 k is
Options
- A3
- B5
- C7
- D11
Correct answer
D. 11
Step-by-step solution
The area covered is maximum if ‘ m ’ is minimum, i.e. m = 1 ∴ Required area ∫ 0 4 4 x - x d x = 2 ⋅ x 3 2 3 2 − x 2 2 0 4 = 4 3 x 3 2 - x 2 2 0 4 = 32 3 - 8 = 8 3 sq. units ∴ k = 8 3 Thus required prime number = 11