Question

If the parabolas y² = 4b(x - c) and y² = 8ax have a common normal, then which one of the following is a valid choice for the ordered triad (a, b, c) ?

(1) (1/2, 2, 3)

(2) (1, 1, 3)

(3) (1/2, 2, 0)

(4) (1, 1, 0)

Answer 1

Correct option: (2) (1, 1, 3)

Explanation:

Answer 2

Correct option: (2) (1, 1, 3)

Explanation:

Equation of normal to y² = 80 x & y² = 46(x - c) having slope ‘m’ is 

y = mx – 4am – 2a m³ & y = m(x – c) – 2bm – bm³