Prove that (cos 2x + cos 3x + cos 8x)/(sin 2x + sin 3x + sin 8x) = tan x
T Tarvel New member Joined Jul 21, 2021 Messages 3 Sep 16, 2021 #1 Prove that (cos 2x + cos 3x + cos 8x)/(sin 2x + sin 3x + sin 8x) = tan x
topsquark Senior Member Joined Aug 27, 2012 Messages 2,370 Sep 16, 2021 #2 It isn't true for all x. Let x = 0. Then the LHS is undefined and the RHS is 0. -Dan
