Find the length of the line segment joining the vertex of the parabola `y^2=4a x` and a point on the parabola where the line segment make and angle `theta` to the `x-a xi sdot`

Explanation

Let the coordinate of the point on the parabola be B`(x_1,y_1)`


Let BO be the line segment


`costheta=(AO)/(OB)` and `sintheta=(y_1)/(OB)`


`:.x_1=OBcostheta ` and `y_1=OBsintheta`


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