. A double ordinate of the parabola
A double ordinate of the parabola y2 = 8px is of length 16p. The angle subtended by it at the vertex of the parabola is
a. π/4
b. π/2
c. π
d. π/3
Best Answer
Correct answer is b
Explanation:
General formula of the parabola,
y2 = 4ax
points are P(α,8p)
also, P = (2pt2,4pt)
8p = 4pt
t = 2
α = 8p
when, tanθ/2 = 8p/8p = 1
θ = π/2
Related questions
