Maths Olympiad Prep

Track / Stage 5 / 35 of 400 #635 of 1964

Problem 635

AIME late
Geometry Difficulty 5.1 Find the answer

We have two perpendicular lines - like the axes of an ellipse - and a tangent (t)(t) with its point of tangency (T)(T). Construct the endpoints of the ellipse's axes (A,B,C,D)(A, B, C, D)! How many solutions are there?

A number or a short expression. Spacing, $ signs and \frac vs / are all fine.

Official solution

Let the tangent touch one of the axes at PP; draw a circle over the diameter OP\overline{O P} and project TT perpendicularly onto this circle in the direction of OP|O P|. OT1\overline{O T_{1}} is the radius of the affine circle from which we obtain AB\overline{A B} and CD\overline{C D} as shown in the figure. There is one solution.

Sándor Gyula (Kölcsey Ferencg. VIII. o. Budapest)

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.