设圆锥底面半径为r,r=x*R,可以算出x=1-a/2π圆锥的容积v为πr²*(R²-r²)&sup0.5v=πx²*R²*（R²-x²*R²）&sup0.5v=πR³*（x&sup4-x&sup6）&sup0.5对变量x&sup4-x&sup6求...