若tanx=2,则2sin平方x-3sin(π-x)sin(π/2-x)=
已知函数fx=(1+1/tanx)sin^x-2sin(x+π/4)sin(x-π/4)
若sin(x+y)=1/2,sin(x-y)=1/3,则tanx/tany等于?
若f(x)=2tanx-2sin
求证(tanxtan2x/tan2x-tanx)/(tan2x-tanx)+√3(sin^2x-cos^2x)=2sin
已知2tanx/1+tanx的平方=3/5求sin(π/4+x)的平方的值
三角函数题.已知tanx=2.求(sin(π-x)cos(2π-x)sin(-x+3π/2))/tan(-x-π)sin
函数f(x)=(1+1/tanx)sin^2x-2sin(x+π/4)sin(x-π/4).若tana=2,求f(a).
已知函数f(x)=2根号3sin平方x-sin(2x-π/3)
sin(x+y)=1\2,sin(x—y)=1\3,求[tan(x+y)-tanx-tany]\[tany的平方tan(
设f(x)=2cosx.sin(x+π/3)-根号3 sin平方x+sinx.cosx
已知函数f(x)=(1+1/tanx)sin(x)^2 -2sin(x+π/4)*cos(x+π/4)
已知tanx=- (2分之1),则sin^2x+3sin^2xcosx-1=