x*dy/dx + y*dx/dx = x*sinx;d(xy)/dx = x*sinx;两边同时对x积分,可得xy = sinx-x*cosx+C;y = (sinx)/x - cosx + C/x,其中C为任意常数.x=π时y=0,带入一般解,可得 C = -π特解为y = (sinx)/x - cosx - π/x...