Question

Equation of the parabola whose directrix is y = 2x - 9 and focus (–8, –2) is

(a) x² + 4y² + 4 xy + 16 x + 2y + 259 = 0 

(b) x² + 4y² + 4 xy + 116 x + 2y + 259 = 0

(c) x² + y² + 4 xy + 116 x + 2y + 259 = 0 

(d) None of these

Answer 1

Correct option  (b) x² + 4y² + 4 xy + 116 x + 2y + 259 = 0

Explanation:

Let any point on it be (x, y), then from definition of parabola, we get

Squaring and after simplification, we get

x² + 4y² + 4 xy +116 x + 2y + 259 = 0 .