已知θ∈(π/2,π),且sin(θ+π/3)=-5/13,则cosθ=?
已知θ∈(π/2,π),且sin(θ+π/3)=-5/13,则cosθ=?
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sinθ+cosθ=1/5,且π/2≤θ≤3π/4,则cos^2-θsin^2θ的值
已知θ∈(5π/2,3π),且sinθ=24/25,则cos(θ/2)等于?
已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4)
已知向量m=(Cosθ,Sinθ)和n(根号2 -Sinθ,Cosθ),且Im+nl= 求Cos(θ/2+π/8)
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α、β≠kπ+π2(k∈Z),且sinθ+cosθ=2sinα , sinθcosθ=sin
已知α∈(0,π/2),且2sinα-sinαcosα-3cosα=0.求[sin(α+π/4)]/[sin2α+cos
已知θ∈(0,π/2)且满足关系logtanθ cosθ=3/2 求logcsc^2θ(sinθ*cosθ)的值.
已知θ∈(0,π/2),且满足关系logtanθCOSθ=2/3,求logcsc^2θ(sinθ*cosθ)的值