设圆柱形容器底面半径为R,高为H,2πR²+2πRH=sH=(s-2πR²)/(2πR)圆柱形容器的容积=VV=πR²H=πR²(s-2πR²)/(2πR)=0.5R(s-2πR²)=0.5sR-πR³V'=0.5s-3πR²另V'=0,0.5s-3π...