已知 y=1\sinθ+2\cos^2θ 求最小值
问题描述:
已知 y=1\sinθ+2\cos^2θ 求最小值
答
sinθ 无平方吗?y=1/sinθ+2/cos^θ=1/sinθ+msin^2θ+2/os^2θ+mcos^2θ-m =1/(2sinθ)+1/(2sinθ)+msin^2θ+2/os^2θ+mcos^2θ-m>=3(m/4)^(1/3)+(2m)^(0.5)-m取等号条件是:1/(2sinθ)=msin^2θ,且 2/os^2...