MathDB
Sides of a triangle

Source:

May 12, 2006
probabilitytrigonometrysymmetryinequalitiesalgebrafunctiondomain

Problem Statement

An angle xx is chosen at random from the interval 0<x<900^\circ < x < 90^\circ. Let pp be the probability that the numbers sin2x\sin^2 x, cos2x\cos^2 x, and sinxcosx\sin x \cos x are not the lengths of the sides of a triangle. Given that p=d/np = d/n, where dd is the number of degrees in arctanm\arctan m and mm and nn are positive integers with m+n<1000m + n < 1000, find m+nm + n.