SOLUTION: Show how both sides equal. 2 cos^2 30 degrees-1 = cos 60 degrees

Algebra ->  Trigonometry-basics -> SOLUTION: Show how both sides equal. 2 cos^2 30 degrees-1 = cos 60 degrees      Log On


   

Question 181070: Show how both sides equal.
2 cos^2 30 degrees-1 = cos 60 degrees
Answer by eperette(173) About Me  (Show Source):
You can put this solution on YOUR website!
things you should know:
cos30= sqr(3)/2
cos60= 1/2
2cos^2(30) - 1 = cos60
2(cos30)^2 -1
2(sqr(3)/2)^2 -1
2(3/4) -1
3/2 -1
1/2
1/2 = cos60