sin^4x-sin^2xcos^2x+cos^4x =(sin^2x+cos^2x)^2-3sin^2xcos^2x 那么这个依据呢?老师
问题描述：
sin^4x-sin^2xcos^2x+cos^4x =(sin^2x+cos^2x)^2-3sin^2xcos^2x 那么这个依据呢?老师
答
针对三角函数的证明,一般都是采取化简的思路来解答.对等式右边进行化简,=(sin^2x+cos^2x)^2-3sin^2xcos^2x =（sin^4x+2sin^2xcos^2x+cos^4x）-3sin^2xcos^2x =sin^4x-sin^2xcos^2x+cos^4x =等式左边所以sin^4x-sin^2...