a,b,c为正数,且acos^2θ+bsin^2Θ扫码下载作业帮拍照答疑一拍即得
问题描述:
a,b,c为正数,且acos^2θ+bsin^2Θ 扫码下载作业帮
拍照答疑一拍即得
答
(√acos^2Θ+√bsin^2Θ)^2-acos^2θ+bsin^2Θ=a(cos^4θ-cos^2θ)+b(sin^4θ-sin^2Θ)+2√(ab)sin^2Θcos^2Θ=-acos^2θsin^2θ-bsin^2θcos^2θ+2√(ab)sin^2Θcos^2Θ=-(√a-√b)^2sin^2Θcos^2Θ(√acos^2Θ+√b...