Question

Упростите задачу
2cos^2(x/2)-cosx

Answer 1

2cos²(x/2)-cosx=2cos²(x/2)-cos²(x/2)+sin²(x/2)=cos²(x/2)+sin²(x/2)=1
Использовал формулу cosx=cos²(x/2)-sin²(x/2)

Answer 2

cosx=2cos²(x/2)-1
2cos²(x/2)-cosx=cosx+1-cosx=1