化简sin^6a+cos^6+3sin^2acos^2a的结果是?
化简sin^6a+cos^6+3sin^2acos^2a的结果是?
已知a(-0,兀且2SIN A-SIN ACOS A-3COS A=0求SIN(+兀/4)/SIN 2A+COS 2A+
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
化简cos^2 a(2cos^2+3)-sin^2 a(2cos^2+3)-4sin^2 acos^2 a+3
化简:sin^2a+sin^2β-sin^2asin^2β+cos^2acos^2β
求证sin^4a+cos^4a=1-2sin²acos²a
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
求证[1]1-2sin acos a/cos²a -sin²a =1-tan a/1+tan a.[
sin²a+cosˇ4a+sin²acos²a 化简
化简sin(#-a)cos(2#-a)cos(-a+3/2*#)/cos(#/2-a)sin(-#-a);#为圆周率的那
化简sin(#-a)cos(2#-a)cos(-a 3/2*#)/cos(#/2-a)sin(-#-a);#为圆周率的那