A hint to get started
Trace a moving midpoint locus from tangent intercepts
For , :
(i) Find and simplify the tangent equation at .
(ii) Hence find Q and R where that tangent meets the x- and y-axes, respectively.
(iii) Find a Cartesian equation for the locus of the midpoint of QR as p varies.
[2011/9740/I/3]
CJC · Lecture · Example 10
Parameterise the midpoint itself, then eliminate p from those two new coordinates.