sin²α+sin²β-sin²αsin²β+cos²αcos²β=1证明恒成立
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 05:26:10
![sin²α+sin²β-sin²αsin²β+cos²αcos²β=1证明恒成立](/uploads/image/z/1606667-59-7.jpg?t=sin%26%23178%3B%CE%B1%2Bsin%26%23178%3B%CE%B2-sin%26%23178%3B%CE%B1sin%26%23178%3B%CE%B2%2Bcos%26%23178%3B%CE%B1cos%26%23178%3B%CE%B2%3D1%E8%AF%81%E6%98%8E%E6%81%92%E6%88%90%E7%AB%8B)
sin²α+sin²β-sin²αsin²β+cos²αcos²β=1证明恒成立
sin²α+sin²β-sin²αsin²β+cos²αcos²β=1证明恒成立
sin²α+sin²β-sin²αsin²β+cos²αcos²β=1证明恒成立
这题对于爷就是下菜!sin²α+sin²β-sin²αsin²β+cos²αcos²β
=sin²α+sin²β(1-sin²α)+cos²αcos²β
=sin²α+sin²βcos²α+cos²αcos²β
=sin²α+cos²α(sin²β+cos²β)
=sin²α+cos²α
=1请速度给分