已知cosθ=-3/5(π/2
已知cos(θ+π/4)=3/5,π/2
已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4)
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tanθ=3,求(3cosθ-5sin^2θcosθ)/sin(π-θ)的值
已知(4sinθ-2cosθ)/(3sinθ+5cosθ)=6/11,求5cos^2θ/(sin^2θ+2sinθcos
已知cosθ=-3/5,∏
已知向量m=(cosθ,-sinθ),n=(根号2+sinθ,cosθ),θ∈(π,3π/2),且cos(θ/2+π/8
已知θ为第三象限角,1-sinθcosθ-3cos^2=0则5sin^2θ+3sinθcosθ=?
已知cos(π/6+θ)=根号3/3,求cos(5π/6-θ)的值
已知cos(π/2+x)=sin(x-π/2) 求sin^3(π-x)+cos(x+π)/5cos(5π/2-x)+3s
已知cos(π/2+a)=2sin(a-π/2)求sin(π-a)+cos(a+π)/5cos(5π/2-a)+3sin
已知cos(π/2+α)=2sin(α-π/2),求[sin^3(π+α)+cos(α+π)]/[5cos(5π/2-α