Question

已知抛物线x^2=2y,过点P(0,1)的直线与抛物线相交于A(x1,y1),B（x2,y2）不同两点

Answer 1

y-1=kx

x^2=2y

(y-1)^2=2k^2y

y^2-(2+2k^2)y+1=0

y1*y2=1