MathDB
Ellipse not parallel to x- or y-axis

Source:

January 1, 2006
conicsellipseanalytic geometrygeometrygeometric transformationreflection

Problem Statement

An ellipse has foci at (9,20)(9,20) and (49,55)(49,55) in the xyxy-plane and is tangent to the xx-axis. What is the length of its major axis?