Parametrics - locus of the midpoint - asap help exam tomorrow

[zinghini]

help asap !! i dont know how to find the locus of the midpoint :/

18.) PQ is a chord of x^2=4ay where P=(2ap, ap^2) and Q(2aq, aq^2).
a) find the coordinates of point N that divides PQ in the ratio 2:3
this was easy, just used ratio formula.

b) find the locus of the midpoint of PQ if pq=2

I have no clue how to find midpoint, i tried midpoint formula but it didn't work, please help!!

[jazz519]

https://drive.google.com/open?id=1P5...4EhNNyaRoVeRds