为什么-[cos²(π/8)-sin²(π/8)]=-cos(π/4)
求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8
sin²π/8 -cos²π/8
求证:1-2sinαcosα/cos²α-sin²α=tan(π/4-α)
求证(1-2sinαcosα)/(cos²α-sin²α)=tan(π/4-α)
α属于(0,π/2)且2sin²α-sinαcosα-3cos²α=0求sin(α+π/4)/sin
8sin(π/32)cos(π/32)cos(π/16)cos(π/8),求值
cos sin π √
cos(π/32)*cos(π/16)*cos(π/8)=
求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8!急救急救
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
f(x)=cos²(π/6)+sinπ/6cosπ/6