(0,+∞)∫(sinx/x)^2dx=(1/2)*(0,+∞)∫(1-cos2x)/x^2dx=(1/2)*(0,+∞)∫1/x^2dx-(1/2)*(0,+∞)∫cos2x/x^2dx=(1/2)*(0,+∞)∫1/x^2dx-(1/2)*(0,+∞)∫cos2x/d(1/x)=(1/2)*(0,+∞)(-1/x)-(1/2)*(0,+∞)cos2x/x+(1/2)...