求解析过程和切入点。
化简(1-sin^6 a-cos^6 a)/(sin^2 a-sin^4 a)，
答案:2 悬赏:60 手机版
解决时间 2021-04-25 02:27
- 提问者网友：欺烟
- 2021-04-24 23:21
最佳答案
- 五星知识达人网友：人间朝暮
- 2021-04-25 00:38
切入点：
sin²a+cos²a=1的代换
全部回答
- 1楼网友：西风乍起
- 2021-04-25 00:44
(1-sin^6 a-cos^6 a)/(1-sin^4 a-cos^4 a)
=[1-(sin^6 a+cos^6 a)]/[(1-sin^4 a-cos^4 a]
=[1-(sin^2 a+cos^2 a)(sin^4 a-sin^2 acos^2 a+cos^4 a)]/[(1-sin^4 a-cos^4 a]
=[1-(sin^4 a-sin^2 acos^2 a+cos^4 a)]/(1-sin^4 a-cos^4 a)
=[1-sin^4 a+sin^2 acos^2 a-cos^4 a]/(1-sin^4 a-cos^4 a)
=1+sin^2 acos^2 a/(1-sin^4 a-cos^4 a)
=1+sin^2 acos^2 a/[(1-sin^4 a)-cos^4 a]
=1+sin^2 acos^2 a/[(1-sin^2 a)(1+sin^2 a)-cos^4 a]
=1+sin^2 acos^2 a/[cos^2 a(1+sin^2 a)-cos^4 a]
=1+sin^2 acos^2 a/[cos^2 a(1+sin^2 a-cos^2a)]
=1+sin^2 acos^2 a/[2sin^2 a*cos^2 a]
=1+1/2
=3/2
我要举报
如以上问答信息为低俗、色情、不良、暴力、侵权、涉及违法等信息，可以点下面链接进行举报！
大家都在看
推荐资讯