1. The problem statement, all variables and given/known data a. tan4x=1 If tanTheta=1, then Theta=pi/4+-npi radians. 4x=pi/4+-npi x=pi/16+-npi/4 b. sin(x+2pi)+sin(x-2pi)=1/2 sinxcos2pi+cosxsin2pi+sinxcos2pi-sin2picosx=1/2 2sinxcos2pi=1/2 sinxcos2pi=1/4 sinx=1/4 arcsin(1/4)=0.2526+-2npi 2. Relevant equations 3. The attempt at a solution So how do you know which one to attach +-npi or +-2npi? I have a slight suspicion that it might be due to periods of trig functions, but I don't trust myself when it comes to math. Thanks.