已知α是第二象限角,化简cosα1−sinα1+sinα+sinα1−cosα1+cosα.
数学人气:537 ℃时间:2019-10-09 11:37:36
优质解答
∵α是第二象限角,
∴sinα>0,cosα<0,
则原式=cosα•
| (1−sinα)(1+sinα) | (1+sinα)2 |
|
+sinα•
| (1−cosα)(1+cosα) | (1+cosα)2 |
|
=cosα•
+sinα•
=-
.
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