
h=2at2+a,k=22at+0
⇒t2=a2h−a and t=ak
⇒a2k2=a2h−a
⇒ Locus of (h,k) is y2=a(2x−a)
⇒y2=2a(x−2a)
Its directrix is x−2a=−2a⇒x=0
The locus of the mid-point of the line segment joining the focus of the parabola y2=4ax to a moving point of the parabola, is another parabola whose directrix is:
Held on 24 Feb 2021 · Verified 6 Jul 2026.
x=a
x=0
x=−2a
x=2a
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