这是我的源代码:#include#includeusingnamespacestd;doubleup=19.0+(61.0/125.0);doubledown=-32.0-(2.0/3.0);doublerectangle=(up-down)*8.0;doublef(doublex){return(pow(x,4.0)/500.0)-(pow(x,2.0)/200.0)-0.012;}doubleg(doublex){return-(pow(x,3.0)/30.0)+(x/20.0)+(1.0/6.0);}doublearea_upper(doublex,doublestep){ret