①sin(-28π/3)②tan(-44π/3)已知sin(π+a)=-1/2,计算:①tan(π/2-a)②cos(27π/2+a)③sin(-a)-[cos(2π-a)] / [tan(a-π)]

①sin(-28π/3)②tan(-44π/3)已知sin(π+a)=-1/2,计算:①tan(π/2-a)②cos(27π/2+a)③sin(-a)-[cos(2π-a)] / [tan(a-π)] ①利用公式sin(π-θ)=sinθ和sin(∏+θ)=-sinθ证明：sin（-θ）=-sinθ②证明tanθsinθ∕tanθ-sinθ=1+cosθ∕sinθ③已知sinα-2cosα+1=0,α≠kπ+π∕2,k∈z求：tan（3π-α）和1∕sin2α-sinαcosα+1的值‍ 化简①sin（π+α）×cos（3π/α）+sin（π/2+α）×cos（π+α）②sin（540°-x）×cos（x-360°）/tan（900°-x）×tan（450°-x）×tan（810°-x）×sin（-x） 高一三角函数计算如题 ①2sin0°+5sin90°-3sin270°+10sin180° ②sinπ/6-√2sinπ/4+4/3sinπ/3+sinπ/6+sin3π/2 ③cos0°+5sin90°-3sin270°+10cos180° ④cosπ/3-tanπ/4+3/4tanπ/6-sinπ/6+cosπ/6+sin3π/2 ⑤sin四次方π/4-cosπ/2+6tan 计算 ①tan600°-cos960°-sin(-300°)② tan（-5π/6）+cos（-23π/4）+sin-17π/3） 已知a是第三象限角,且f(a)=sin(π-a)cos(2π-a)tan(-a+3π/2)*tan(a)/sin(∏+a)①化简f（a）②若cos（a-3 ①化简1+cos(π/2 +α)*sin(π/2 -α)*tan(π+α)②计算(1)tan(π/5)+tan(2π/5)+tan(3π/5)+tan(4π/5) (2)sin(-60°)+cos(225°)+tan135°(3)cos(π/5)+cos(2π/5)+cos(3π/5)+cos(4π/5)（4）tan10°+tan170°+sin1866°-sin(-606°) ①已知cosα= -12/13,求sinα,tanα的值.②已知tanα=3/4,求sinα,cosα的值. tan²α-sin²α=tan²α×sin²α（cosα-1）²+sin²α=2-2cosαsin四次方x+cos四次方x=1-2sin³xcos²x已知tanα-3求：①4sinα-2cosα/5cosα+3tanα②sinαcosα③（sinα+cosα）²已知cosα=1/4求sinα 高一数学~任意角的三角函数已知3sinα=-cosα,求①2倍sinα的平方+3倍cosα的平方/sinα的平方+sinαcosα②1+sinαcosα求证：tanαsinα/tanα-sinα=1+cosα/sinα 已知α、β≠kπ+π/2（k∈Z）,且sinθ+cosθ=2sinα,① sinθcosθ=sin^2α.② 求证：(1-tan^2α)/(1+tan^2α)=(1-tan^2β)/(2[1+tan^2β]) Sinπ/3Tanπ/3+tanπ/6COSπ/6－Tanπ/4COSπ/2 sin(2π-α)tan(α+3π)tan(-α-π)/tan(α-3π)cos(π-α) 已知sinα=2sinβ,tanα=3tanβ,求αcos^2的值① 已知sin =2sinβ，tan =3tanβ，求 的值. 化简[sin(π-α)cos(3π-α)tan(-α-π)]/[tan(4π-α)sin(5π+α)] ①sin(α+180°)cos(-α)sin(-α-180°)和②sin³（-α）cos（2π+α）tan（-α-π）化简 tan(a+π/4)=2,则cos2a+3sin^2a+tan a= ①(2cosα+3sinα)/(3cosα+sinα) (2+3tanα)/(3+tanα)2(sinα)^2+sinαcosα-3(cosα)^2②tanα√((1/((sinα)^2))-1)第二个可以看图：