已知cos θ=1/3,θ∈(0,π),则cos(3π/2+2θ)
已知cosθ=13,θ∈(0,π),则cos(π+2θ)等于( )
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 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=?
①化简[sin(2π+α)*cos(7π-α)]/cos(-α)②已知cosθ=-3/5,θ∈(π/2,π),求sin(
急求已知根号3sinθ-sin(π/2-2θ)/cos(π+θ)×cosθ=1 θ ∈(0,π) 求θ的值
已知cos(θ+π/4)=3/5,π/2
已知tan(θ+π/4)=-2,求cosθ平方+sinθcosθ-1
已知sinθ+√3cosθ=2cos(θ-φ),求tanφ.(0
θ∈(0,π/2),比较cosθ、sin(cosθ)、cos(sinθ)的大小
cosθ^2+cos(θ+2π/3)^2+cos(θ-2π/3)^2 计算
已知cosα=1/3,α属于(π,2π),则cosπ/2等于