Find the locus of point of intersection of tangent to the parabola `y^2=4ax` (i)which are inclined at an angle `theta` to each other. (ii) which intercept constant length c on the tangent at the vertex (iii) such that the area of `DeltaABC` is constant c; where A and B are the points of intersection of tangents with the y-axis and R is a point of intersections of tangents.