SOLUTION: prove identity cos(2pi-x)=cosx

Algebra ->  Trigonometry-basics -> SOLUTION: prove identity cos(2pi-x)=cosx      Log On


   

Question 738676: prove identity
cos(2pi-x)=cosx
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

cos%282pi-x%29=cos%282pi%29cos%28x%29%2Bsin%282pi%29sin%28x%29.........since cos%282pi%29=1 and sin%282pi%29=0, we will have
cos%282pi-x%29=1%2Acos%28x%29%2B0%2Asin%28x%29
cos%282pi-x%29=cos%28x%29