Prove that the tangents drawn on the parabola `y^(2)=4ax`at points x = a intersect at right angle.

The angle between the tangents to the parabola y^(2)=4ax at the points where it intersects with the line x-y-a= 0 is

The angle between the tangents to the parabola y^(2)=4ax at the points where it intersects with the line x-y-a= 0 is

The angle between tangents to the parabola y^(2)=4ax at the points where it intersects with teine x-y-a=0 is (a>0)

The angle between tangents to the parabola y^2=4ax at the points where it intersects with teine x-y-a = 0 is (a> 0)

The angle between tangents to the parabola y^2=4ax at the points where it intersects with teine x-y-a = 0 is (a> 0)

If the two tangents drawn from a point P to the parabola y^(2) = 4x are at right angles then the locus of P is