sin(π/2+θ)=3/5,则cosθ=

sin(π-θ）+cos(2π-θ）/cos(5π/2-θ)+sin(3π/2+θ)=2,则sinθcosθ=______ (sinθ+cosθ)/(sinθ-cosθ)=2,则sin(θ-5π)*sin(3π/2-θ)= 若（sinθ+cosθ）/（sinθ-cosθ）=2,则sin（θ-5π）*sin（3π/2-θ）等于? cot(π+θ)=2,则(3sinθ-cosθ)/(sinθ+cosθ)=? 已知sinθsinβ=-4/7,则cosθcosβ∈已知tan(π-θ)=3,求下式的值 (5xin^3θ+cosθ)/(2cos^3θ+sin^2θcosθ) 求值:已知sinθ+cosθ=1/5,已知θ∈(0,π).求(1)sinθ*cosθ(2)sinθ-cosθ(3)tanθ 已知θ为第三象限角,1-sinθcosθ-3cos^2=0则5sin^2θ+3sinθcosθ=? sinθ-cosθ=1/2,则sin^3θ-cos^3θ=?. 若sin（θ-π）=2cos（2π-θ）求（1）sinθ+5cosθ/sinθ-3cosθ (2)sinθcosθ的值 已知tanθ=3,求(3cosθ-5sin^2θcosθ)/sin(π-θ)的值 已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4)sin平方θ+(2/5)cos平方θ已知sin(θ+kπ)=-2cos (θ+kπ)求⑴ 4sinθ-2cosθ/5cosθ+3sinθ⑵(1/4)sin平方θ+(2/5)cos平方θ 若[sin(π-θ)+cos(2π-θ)]/[cos(5π/2-θ)+sin(3π/2+θ)]=2,求sinθ*cosθ的值若[sin（π-θ）+cos（2π-θ）]/[cos(5π/2-θ)+sin(3π/2+θ）]=2,求sinθ*cosθ的值 已知sin(θ+kπ)=-2cos(θ+kπ),k∈Z,求4sinθ-2cosθ/5cosθ+3sinθ①4sinθ-2cosθ/5cosθ+3sinθ ②sin²θ+2/5cos²θ 2sinθ+cosθ/sinθ-3cosθ=-5,求cos2θ+4sinθ 若f(cosθ)=sin^2-3cosθ,则f(2cos π/3 )=_____ 已知sinθ+cosθ=1/5,且π/2≤θ≤3π/4,则cos^2-θsin^2θ的值 已知(4sinθ-2cosθ)/(3sinθ+5cosθ)=6/11,求5cos^2θ/(sin^2θ+2sinθcosθ-3cos^2θ) 若sin θ-cos θ 分之sin θ+cos θ=2 则sin θcos θ 是