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The point A is the vertex of the parabola

y=x2−2x+2

The point B lies on the parabola to the right of A. The point M is the midpoint of AB.

A triangle PQR is formed, where

  • P,Q are the points of intersection between the parabola and the horizontal line through M

  • R lies on the parabola directly below M.

Given that the area of the triangle PQR is 2, find the coordinates of B.


Your diagram should look like this:

Parabola with inscribed triangle

A has coordinates (1,1). If we let B have x-coordinate b, then we have B=(b,b2−2b+2).


The coordinates of M are

(b+12,b2−2b+32)

R has the same x-coordinate as M

P,Q have the same y-coordinate as M.


After finding R in terms of b, you should find that the height of the triangle is

(b−12)2

After finding P and Q in terms of b, you should find that the base of the triangle is

2(b−1)