∫1/[sin(2x)+2sin x]dx=∫1/[2sinxcosx+2sin x]dx=∫1/(2sinx*[cosx+1]) dx=∫1/(sinx*[2cos^2(x/2)]) d(x/2)=1/2∫1/sinx dtan(x/2)=1/2∫[1+tan^2(x/2)]/[2tan(x/2)] dtan(x/2)=1/4∫[1/tan(x/2) ]+tan(x/2) dtan...