sin²π/3-cos²π/4怎么算
α属于(0,π/2)且2sin²α-sinαcosα-3cos²α=0求sin(α+π/4)/sin
sin²β+cos^4+sin²βcos²β为多少,怎么算
设f(α)=2sinαcosα+cosα/1+sin²α+cos(3π/2+α)-sin²(π/2+
已知tan(3π+α)=2,求:1、(sinα+cosα)²;2、sinα-cosα/2sinα+cosα
已知3π/4最好把tan化成sin/cos,cot化成cos/sin算,因为我是这样的,然后算得sin@cos@=-3/
(sinθcosπ/3)-(cosθsinπ/3)怎么化简得sin(θ-π/3)
求证:1-2sinαcosα/cos²α-sin²α=tan(π/4-α)
求证(1-2sinαcosα)/(cos²α-sin²α)=tan(π/4-α)
cosπ/3+tanπ/4+3tan²π/6+sinπ/2+cosπ+sin3π/2等于?.
sin(a-π/4)+cos(a+π/4)怎么解?
已知f(x)=sin²wx+2倍根号3 sin(wx+π/4)cos(wx-π/4)-cos²wx-
已知函数f(x)=cos(2x-π\3)+sin²x-cos²x