sin^2a+sin^2a.cos^2a+cos^2a化简

求证1+sin a+cos a+2sin acos a/1+sin a+cos a=sin a+cos a sin/cos^2a+cos/sin^2a最小值 求证:sin 2a/1+sin a+cos a=sin a+cos a-1急 化简:sin(-a)cos(2π+a)sin(-a-π) 化简Sin A + Sin 2A / 1+cos A + sin^4+sin^2cos^2+cos^2a= 一个简单的三角函数题(sin a + cos a)/(sin a - cos a) 则 sin a *cos a=(sin a + cos a)/(sin a - cos a) = 2 则 sin a *cos a= 化简(sin a^2/cos a +cos a)*cot a 证明Cos^A-Sin^A=1-2Sin^A=2Cos^A-1=cos^a-sin^a sin 2a+2sin方a/ 1+tan a =2sin a cos a 化简sin^2a-cos^2a cos^2a+sin^2a=? sin^2A/cos^2A=? 化简sin(a/2)cos(a/2) 求证 1+sin a+cos a+2sin a*cos a/1 +sin a +cos a = sin a+ cos a 有什么思路! (cos a)^4+(sin a)^2*(sin a)^2+(sin a)^2=? cosA+cos^2A=1,sin^2A+sin^4A+sin^8A (1-sin^6a-cos^6a)/(sin^2a-sin^4a)