PQ is a double ordinate of a parabola `y^2=4a xdot` Find the locus of its points of trisection.

Explanation

For the parabola `y^2 = 4ax` we have,

`x = at^2, y = 2at`.


So, we can consider point `P(at^2, 2at)` and `Q(at^2, - 2at)`, then its points of trisection have ordinates `y_1` and `y_2` where:

`y_1 = (- 2at + 4at) / 3 = (2at)/3`

`y_2 = (- 4at + 2at) / 3 = (- 2at)/3`


For both of these points,

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