JEE Main2016MathematicsApplication of DerivativesActual
Let C be a curve given by y x = 1 + 4 x - 3 , x > 3 4 . If P is a point on C, such that the tangent at P has slope 2 3 , then a point through which the normal at P passes, is :
Options
- A1 , 7
- B3 , - 4
- C4 , - 3
- D2 , 3
Correct answer
A. 1 , 7
Step-by-step solution
Given, y x = 1 +   4 x - 3 So, d y d x = 1 2 4 x - 3   × 4 = 2 3 ⇒ 4 x - 3 = 9 ⇒ x = 3 So, y = 4 Equation of normal at P 3 ,   4 is y - 4 = - 3 2 x - 3 i.e., 2 y - 8 = - 3 x + 9 ⇒ 3 x + 2 y - 17 = 0 Hence only option A is satisfying the equation.