A point P in the first quadrant, lies on y2=4ax, a > 0, and keeps a distance of 5a units from its focus. Which of the following points lies on the locus of P?
An equilateral triangle is inscribed in the parabola y2=4ax, such that one of the vertices of the triangle
coincides with the vertex of the parabola. The length of the side of the triangle is: