应该是求动点G的轨迹,不是Q吧
G(x,y)
xG+xM=2xP
xP=(x+2)/2
yP=(y+3)/2
yP=(xP)^2+2xP+3
(y+3)/2=[(x+2)/2]^2+2*(x+2)/2+3
y=0.5x^2+4x+9