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? 已知(4sinθ-2cosθ)/(3sinθ+5cosθ)=6/11,求5cos^2θ/(sin^2θ+2sinθcos 已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4) 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=?. 已知tanθ=3,求(3cosθ-5sin^2θcosθ)/sin(π-θ)的值 2sinθ+cosθ/sinθ-3cosθ=-5,求cos2θ+4sinθ 若sin θ-cos θ 分之sin θ+cos θ=2 则sin θcos θ 是 ①化简[sin(2π+α)*cos(7π-α)]/cos(-α)②已知cosθ=-3/5,θ∈(π/2,π),求sin( 已知sinθ+cosθ=1/5,且π/2≤θ≤3π/4,则cos^2-θsin^2θ的值