已知 cosθ=-(3/5).且θ∈(π,3π/2)求cosθ/2的值.
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
已知θ∈(0,π/2),且满足关系logtanθCOSθ=3/2 求logcsc^2θ(sinθ*cosθ)的值.
已知tanθ=3,求(3cosθ-5sin^2θcosθ)/sin(π-θ)的值
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
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2sinθ+3cosθ=2,求sinθ+cosθ的值
已知三角型abc三内角a b c 成等差数列,且a-c=π/3,求cos^2a+cos^2b+cos^c的值
已知sin(θ+kπ)=2cos[θ+(k+1)π],k∈Ζ,求4sinθ-2cosθ/5cosθ+3sinθ的值
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θ∈(-π/2,0),cosθ=13,求sinθ+cos(θ-π/4)的值