SOLUTION: sin(x/2)cos(x/2)(1-2sin^2(x/2))

Algebra ->  Trigonometry-basics -> SOLUTION: sin(x/2)cos(x/2)(1-2sin^2(x/2))      Log On


   

Question 1144157: sin(x/2)cos(x/2)(1-2sin^2(x/2))
Answer by ikleyn(52858) About Me  (Show Source):
You can put this solution on YOUR website!
.

First,   sin(x/2)cos(x/2) = %281%2F2%29%2Asin%28x%29.


Second,  1-2sin^2(x/2)  = cos(x).


Therefore,  sin(x/2)cos(x/2)(1-2sin^2(x/2)) = %281%2F2%29%2Asin%28x%29%2Acos%28x%29 = %281%2F4%29%2Asin%282x%29.    ANSWER

------------

You need to know basic Trigonometry formulas for multiple arguments  (for double arguments,  in this case).

See the lesson
    - FORMULAS FOR TRIGONOMETRIC FUNCTIONS
in this site.