# Math Help - Express f(x) in form of f(x)=Acos(Bx-C)

1. ## Express f(x) in form of f(x)=Acos(Bx-C)

a) express f(x) in form of f(x)=Acos(Bx-c) where -pi/2<C<pi/2
f(x)= 3cos2x-/sqrt sin2x
I don't have any idea how to start...

2. Originally Posted by dorkymichelle
a) express f(x) in form of f(x)=Acos(Bx-c) where -pi/2<C<pi/2
f(x)= 3cos2x-/sqrt sin2x
I don't have any idea how to start...