Question
Question: An equilateral triangle is inscribed in the parabola y<sup>2</sup> = 4x, whose one vertex is at the ...
An equilateral triangle is inscribed in the parabola y2 = 4x, whose one vertex is at the vertex of the parabola. The length of its side is
A
43
B
23
C
163
D
83
Answer
83
Explanation
Solution
Let A = (at2, 2at), B = (at2, -2at) are the other two vertices of the equilateral triangle.
∴ tan300 =
⇒ t = 23
∴ The length of the side AB = 4at
= 4.23
= 83