(3sin^2a/2-2sina/2cosa/2+cos^2a/2)/tana+cota(3sin^2a/2-2sina/2cosa/2+cos^2a/2)/（tana+cota）=?

1- sin(2π/3 - a)/sina 已知(sina+cosa)/(sina-cosa)=3 则2sin'a+(sina-cosa)'=? sin^2a=(sina)^2对吗 sinA=x,sin(A/2)=? sin(2A)sinA的周期是多少 若3sin²a+sin²β=2sina,求2sina+sin²β 证明sin^2a+sin^2β+1>sina*cosa+sina+sinβ sinA+sin(120-A)=3/2 求A度数 sinA=3sin(2π/3-A) SINA=?sinA=3sin(2π/3-A) SINA=?答案是-3√3cosA 已知3SIN^2A+2SIN^2B=5SINA,求SIN^2A+SIN^2B范围 若(sina+cosa)/(sina-cosa)=2,则sin(a-5派)*sin(3派/2-a)等于? 若(sina+cosa)/(sina-cosa)=2,则sin(a-5pai)*sin(3pai/2-a)等于? sin(2a+β)/sina-2cos(a+β)=sinβ/sina sin(a-2π)*sin(π+a)为什么等于sina(-sina)啊…… 设(sina)^2-sina-2(cosa)^2=0,求sin(a-3π/2) sinA+sin(150-A)怎么转化到{（根号3 +2）/2}sinA+1/2cosA 已知tana=-3,求sina+2cosa/cosa-3sina和sin^2a-sinacosa 2sin²A-7sinA+3=0,求sinA得多少