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Recover a hyperbola from tangent-intercept midpoints

The curve CC has x=3/tx=3/t, y=2ty=2t.

(i) The line y=2xy=2x cuts CC at AA and BB. Find the exact length of ABAB. marks

(ii) The tangent at P=(3/p,2p)P=(3/p,2p) meets the x-axis at DD and the y-axis at EE. Let FF be the midpoint of DEDE. Find the cartesian equation of the curve traced by FF as pp varies. marks

[2017/II/1]

CJC · Review problems · Question 11

Compute the two tangent intercepts before averaging their coordinates.

Read the worked solution