若sin(π/4+α)=2/5,则sin2α等于
来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/29 18:05:57
若sin(π/4+α)=2/5,则sin2α等于若sin(π/4+α)=2/5,则sin2α等于若sin(π/4+α)=2/5,则sin2α等于sin2α=-cos(π/2+2α)=-[1-2sin&
若sin(π/4+α)=2/5,则sin2α等于
若sin(π/4+α)=2/5,则sin2α等于
若sin(π/4+α)=2/5,则sin2α等于
sin2α
=-cos(π/2+2α)
=-[1-2sin²(π/4+α)]
=-[1-2*(2/5)²]
=-(1-8/25)
=-17/25
若sin^2β-sin^2α=m,则sin(α+β)sin(α-β)
若(sinα+cosα)/(sinα-cosα)=2 则sin(α-5π)·sin(3π/2-α)=?
若sinα+cosα/sinα-cosα=2,则sin(α-5π)*sin(3π/2-α)等于?
若sinα=1/2,则sin(π/4-α)cos(π/4-α)=
若sin(α-3π)=2cos(α-4π),则sin(α-π)+5cos(5π-α)/2sin(3/2π-α)-sin(-α)的值为
若sin(θ/2)=4/5,且sinθ
sin(π-α)=-2sin(π/2+α),则sinαcosα等于
已知sin(3π-α)=-2sin(π/2+α)则sinαcosα
若sin(α+β)=1/2,sinαcosβ=3/4,则sin(α-β)=
sinα=4/5,π/2
若(sinα+cosα)/(sinα-cosα)=2,求sin(α-5π)sin(3π/2-α)的值
2sinα-3cosα/4sinα-9cosα=-1,则9sin^2α-3sinαcosα-5=
若sin(π+α)+sin(-α)=-m,则sin(3π+a)+2sin(2π-a)的值为?
化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)=
若(sinθ+cosθ)/(sinθ-cosθ)=2,则sin(θ-5π)*sin(3π/2-θ)等于?
若tan(π-α)=2,则2sin(3π+α)cos(5/2π+α)+sin(3/2π-α)sin(π-α)的值为?
若sin (π/4+α)sin(π/4-α)=-1/8,则2sin²α+tanα-1/tanα-1的值为
已知sinα=4分之5,求下列三角函数值 sin(-α) sin(派-α) sin(派+α) sin(2派-α)