证明sin^2a+sin^2β+1>sina*cosa+sina+sinβ
sina(cosa)^3=1/4sin 2a+1/8sin 4a证明过程
(2sin^2a+sin2a)/(1+tana) 整理 =[2sina(sina+cosa)]/[(sina+cosa)
sina+cosa/sina-cosa=2 求sin^2a-2sinacosa+1
证明1-COS^2α/(SINα-COSα)-SINα+COSα/(TAN^2a-1)=SINa+COSa
已知sin a+cos a=1/2 sina*cosa=?cos a/sina+sina/cosa=?
Sin^4a+Sina*Cosa+Cos^2a化简
a、β喂锐角,sina/cosβ+sinβ/cosa=2 求a+β
cos^2a-sin^2a=(cosa+sina)(cosa-sina)吗?
已知sin(pai-a)-2cosa=0若sina
已知tana=3,求①sina+cosa/2sina-cosa ②sin²a+sina·cosa+3cos
若sinA+cosA/sinA-cosA=2,则sin(A-5π)*sin(3π/2-A)等于?
若(sina+cosa)/(sina-cosa)=2,则sin(a-5pai)*sin(3pai/2-a)等于?