# Insanely easy question - trig functions, need a quick question answered

by andrew.c
 P: 47 1. The problem statement, all variables and given/known data I need to solve the equation $$cos 5x + cos 3x = cos x$$ Do the first two terms add together to be cos 8x? Then use double angle formula to solve?
 Quote by andrew.c 1. The problem statement, all variables and given/known data I need to solve the equation $$cos 5x + cos 3x = cos x$$ Do the first two terms add together to be cos 8x? Then use double angle formula to solve?