Prove that the algebraic sum of the ordinates of intersection of a circle and a parabola is 0 I consider two curves $x^2=4ay$ and $x^2+y^2=\lambda^2$
So
$$y^2+4ay-\lambda^2=0$$
And $$y_1+y_2\not =0$$
I just want to whether the question itself is right or not

The equation $y^2+4ay-\lambda^2=0$ has the solutions
$$y_{1/2}=-2a \pm \sqrt{4a^2+\lambda^2}.$$
Hence
$$y_1+y_2=-4a.$$
