若3π/2
若3π/2
若3π/2
若3π/2
若3π/2
若3π/2
若cos(π+α)=-1/2,3π/2
若cos(π+a)=-1/2 ,3π/2
若cos(π+α)=-1/2,3/2π
若cos(π+α)=-1/2,3/2π
若cos(π+a)=-1/2,3/2π
若集合A={x|π/3+2kπ
若集合A={α|π/3+2kπ
三角函数的题:若3π/2
若cos(π/2-a)=3/5,a∈(π/2,π),tana=
若 θ ∈( π /2, π ),则√[1-2sin( π + θ )*sin(3 π /2- θ )]
在三角形abc中若cos(π/2+A)sin(3π/+B)tan (C-π)
已知sin(a+π/4)sin(a-π/4)=1/3,若π/2
若α∈(π/2,π),sin(α+π/6)=3/5,sinα=