Question

Simplify the following, where k represents any integer: cos(2kpi-x)(-sin(2kpi-x))

a. -cosx*sinx
b. (1/2)sin(2x)
c. cos((1/2)x)^2
d. cos(x)^2*sin(x)^2
e. undefined

Answer 1

= cos( -x ) * [ - sin( - x ) ] = cosx * sinx ;
cosx * sin x is the right answer !