Hi. I got a question here is can't seem to solve.
Tangents at P(x_1,y_1) and Q(x_2,y_2) from the curve x^2=4ay intersect at M(\frac{2a(y_2-y_1)}{x_2-x_1},\frac{x_1y_2-x_2y_1}{x_2-x_1})
Using x_1^2=4ay_1 \and\ x_2^2=4ay_2, show M is (\frac{x_1+x_2}{2},\frac{x_1x_2}{4a})
I've got the...