JEE Advanced2017MathematicsParabolaActual
If a chord, which is not a tangent, of the parabola y 2 = 16 x has the equation 2 x + y = p , and midpoint (h, k), then which of the following is (are) possible value(s) of p , h and k ?
Options
- Ap = - 2 , h = 2 , k = - 4
- Bp = 5 , h = 4 , k = - 3
- Cp = - 1 , h = 1 , k = - 3
- Dp = 2 , h = 3 , k = - 4
Correct answer
D. p = 2 , h = 3 , k = - 4
Step-by-step solution
Equation of chord with mid point ( h ,   k ) : k . y - 16 x + h 2 = k 2 - 16 h ⇒ 8 x - k y + k 2 - 8 h = 0   Comparing with 2 x + y - p = 0 , we get k = - 4 ; 2 h - p = 4 Only p = 2 ,   h = 3 ,   k = - 4 satisfies above relation.