设底面半径R,高=(1-4R)/2,体积=V=πR²(1-4R)/2=πR²/2-2πR³求导:V'=πR-6πR²V'=0,πR-6πR²=0,R1=0(舍),R2=1/6体积最大值=πR²/2-2πR³=π(1/6)²/2-2π(1/6)³=π/21...