Find set of all points for a regular triangular pyramid
Source: First Zhautykov Olympiad 2005, Problem 3
December 22, 2008
geometry3D geometrypyramidgeometry unsolved
Problem Statement
Let SABC be a regular triangular pyramid. Find the set of all points D (D! \equal{} S) in the space satisfing the equation |cos ASD \minus{} 2cosBSD \minus{} 2 cos CSD| \equal{} 3.