sin^4a-sin^2acos^2a+cos^2a=1

求证sin^4a+cos^4a=1-2sin^2acos^2a sin^4A+cos^2A+sin^2Acos^2A=? sin^4a-sin^2acos^2a+cos^2a=1 求证1+sin a+cos a+2sin acos a/1+sin a+cos a=sin a+cos a sin^6 a+cos^6 a+3sin^2 acos^2a=(sin^2 a+cos^2 a)(sin^4 a+cos^4 a-sin^2 acos^2 a)是如何计算出的 sin4次方a+sin²acos²a+2cos²a+sin²a= ? 2sin^2acos^2a等于多少 sin^6a+cos^6a+3sin^2acos^2a的值为? 求证(1-sin^2Acos^2A)(cos2A)=cos^6A-sin^6A 求证sin^6A+cos^6A=1-3sin^2Acos^A 已知sin a+cos a= -1/5 求1）sin acos a 2）sin a-cos a Sin^4a+cos^4a怎么=（sin^2a+cos^2a)-2sin^2acos^2a的.求详解.在线等 急.三角函数：化简（sin^2a*cos^4a+sin^4acos^2a)/(1-sin^4a-cos^4a) 已知cos2a=（1/4),求cos^4a+sin^4+sin^2acos^2a的值 2sin(2)Acos(2)A 怎么化为1-1/2sin（2）2A 化简sin^6a+cos^6+3sin^2acos^2a的结果是? 已知tan a =-4,求下列各式的值 (1)sin^2 a (2)3sin acos a (3)cos^2 a-sin^2 a (4)4sin a已知tan a =-4,求下列各式的值 (1)sin^2 a (2)3sin acos a (3)cos^2 a-sin^2 a (4) (4sin a-2cos a)/(5cos a+3sin a) a为任意角 已知tan a =-4,求下列各式的值 (1)sin^2 a (2)3sin acos a (3)cos^2 a-sin^2 a (4)4sin a已知tan a =-4,求下列各式的值 (1)sin^2 a (2)3sin acos a (3)cos^2 a-sin^2 a (4) (4sin a-2cos a)/(5cos a+3sin a) a为任意角