(2sin²a+2sinacosa)/[1+(sina/cosa)]=2sinacosa怎么解出来的
sina+cosa/sina-cosa=2 求sin^2a-2sinacosa+1
已知sina+cosa=1/2,求sinacosa和sin^3a+cos^3a
sinacosa=1/2,tana+cosa/sina的值
sina+cosa=根号2,求sinacosa
已知sina+cosa=0,求sin^2a+2sinacosa+cos^2a
tana=2 5-2sinacosa=?(sina+cos^3a)/cosa+sin^3a=?
已知sina+cosa=根号2,求sinacosa,tana,sin^4a+cos^4a
tana=2,求2sina+cosa/sina-cosa和sin^2a-2Sinacosa+3cos^2a
证明1+sina+cosa+2sinacosa/1+sina+cosa=sina+cosa,
已知6sina+sinacosa-2cosa=0,a∈[90,180),求sin(2a+60度)的值
已知sina+cosa=根号2,求sinacosa的值
已知sinA=3/2-cosA,求sinAcosA的值