(sinx*cosx)/(cosx+1+sinx)=1/2[1+2sinx*cosx-1]/(cosx+1+sinx)=1/2[(cosx+sinx)^2-1]/(cosx+sinx+1)=1/2[(cosx+sinx+1)(cosx+sinx-1)]/(cosx+sinx+1)=1/2(cosx+sinx-1)=√2/2(√2/2cosx+√2/2sinx)-1/2=√2/2sin(x+π/4)-1/2
