高一数学~~~急急急急~~~在线~

2025-02-23 05:33:42
推荐回答(1个)
回答1:

2R*sinx=h,2R*cosx=2r(x为arctan(h/2r))V=3.14*(R*cosx)^2*2Rsinx=2*3.14*R^3cos^2x*sinx=2*3.14*R^3√(cos^2x*cos^2x*2sin^2x)/√2<=2*3.14*R^32*3.14*R^3√(cos^2x+cos^2x+2sin^2x)/√2=2*3.14*R^3*√2/√2=2*3.14*R^3当且仅当cos^2x=2sin^2x时,即tanx=1/√2时取等