设sinA-cosA=1/2,求“sinA的三次乘cosA+cosA的三次乘sinA”的和!

设cosa+(cosa)^2=1,求(sina)^2+(sina)^6+(sina)^8的值 设(sina)^2-sina-2(cosa)^2=0,求sin(a-3π/2) sina=2cosa,求(1)3sina+2cosa(2)sin²a+sina×cosa+3 sina+cosa/sina-cosa=2 求sin^2a-2sinacosa+1 设sinA-cosA=1/2,求“sinA的三次乘cosA+cosA的三次乘sinA”的和! tana=sina/cosa=1/4,sin^2+cos^2=1,求sina=? (1-tana)/(1+tana)=2求(1)sina+cosa/(sina+2cosa) (2)sina-cosa(3)sin^2a-3cos^2a+1 已知tana/tana-1=-1,求下列各式的值（1）sina-3cosa/sina+cosa(2)sin^2a+sina*cosa+2 已知tana/（tana-1）=-1,求下列各式的值（1）sina-3cosa/sina+cosa(2)sin^2a+sina*cosa+2 1:已知sina+cosa=根2求sina cosa sin(4方)a+cos(4方)的值2:已知:sina+cosa=1/5(0 sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa tana=-1/2,求2cosa-sina/sina+cosa 已知2sina=cosa+1,求sina+cosa 已知sinα=2cosα,求sina+5cosa/-2cosa+sinasina+5cosa/-2cosa+sina sina+sina=1 求cosa+cosa 已知tana=-3,求sina+2cosa/cosa-3sina和sin^2a-sinacosa 已知sinA=1/5,求2sin(A+B)cosA-sin(2A+B)