Answers

2015-01-13T08:08:52+08:00
Sinα(cotα+tanα)
=sinα(cosα/sinα + sinα/cosα)
=sinα(cosα/sinα)+sinα(sinα/cosα)
=cosα+sin²α/cosα
=(cos²α+sin²α)/cosα

since cos²α+sin²α=1
therefore,
1/cosα or secα
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