Choose the most appropriate answer:The parabola y2 = 4ax passes throug

1.	Choose the most appropriate answer:The parabola y2 = 4ax passes through the point (2, -6), the the length of its latus rectum is …(a) 9 (b) 16 (c) 18 (d) 6
Answer» (c) 18 The given parabola is y² = 4ax Since it passes through (2, -6) ∴ (-6)² = 4a(2) ⇒ 36 = 8a a = 36/8 = 9/2 Length of the latus rectum = 4a = 4(9/2) = 18

Choose the most appropriate answer:The parabola y2 = 4ax passes through the point (2, -6), the the length of its latus rectum is …(a) 9 (b) 16 (c) 18 (d) 6

Answer»

(c) 18

The given parabola is y² = 4ax

Since it passes through (2, -6)

∴ (-6)² = 4a(2)

⇒ 36 = 8a

a = 36/8 = 9/2

Length of the latus rectum = 4a = 4(9/2) = 18