f(x)=(3sinx-4cosx)|cosx|分二种情况讨论（1）当x∈[-π/2+2kπ,π/2+2kπ],其中k∈Zf(x)=(3sinx-4cosx)cosx=3sinxcosx-4cos^2x=3/2(sin2x)-2(1+cos2x)=[(3sin2x-4cos2x)/2]-2 =5[(3/sin2x-4/5cos2x)/2]-2 =5sin(2x+...