高数微积分问题sinx/y dx该怎样计算原函数是：-ycosx/y
∫[0：π/2]dy∫[0：y²]sin(x/y)dx=-∫[0：π/2]ydy·cos(x/y)|[0：y²]=∫[0：π/2](y-ycosy)dy=(½y²-ysiny-cosy)|[0：π/2]=[½·(π/2)²-(π/2)sin(π/2)-cos(π/2)]-(½·0²-0·sin0-cos0)=⅛π²-½π+1
如图
