NTA Abhyas JEE Main2020MathematicsApplication of DerivativesPractice
The acute angles between the curves y = 2 x 2 - x and y 2 = x at 0,0 and 1,1 are α and β respectively, then
Options
- Aα - β = 0
- Bα + β = 0
- Cα > β
- Dα < β
Correct answer
A. α - β = 0
Step-by-step solution
y = 2 x 2 - x ⇒ d y d x = 4 x - 1 Let, m 1 = 4 x - 1 y 2 = x ⇒ 2 y d y d x = 1 Let, m 2 = d y d x = 1 2 y At P 0,0 ,   m 1 = - 1 ,   m 2 → not defined Angle α = π 4 At Q 1,1 ,   m 1 = 3 ,   m 2 = 1 2 β = t a n - 1 3 - 1 2 1 + 3 2 = π 4