JEE Main2012MathematicsParabolaActual
The chord P Q of the parabola y^2=x , where one end P of the chord is at point (4,-2) , is perpendicular to the axis of the parabola. Then the slope of the normal at Q is
Options
- A-4
- B- 1 4
- C4
- D1 4
Correct answer
A. -4
Step-by-step solution
Point P is (4,-2) and P Q x -axis So, Q=(4,2) Equation of tangent at (4,2) is aligned & y y₁= 1 2 (x+x₁ ) & 2 y= 1 2 (x+2) 4 y=x+2 & y= x 4 + 1 2 aligned So, slope of tangent = 1 4 Slope of normal =-4