Answers

2014-10-20T20:27:03+08:00
Tanxsinx + cosx
= ( sinxsinx)cosx + cosx      / tanx =sinx/cosx
 = sin²/cosx + cosx
= (sin²x+cos²x)cosx          / sin²x+cos²x =1
=  1/cosx  = secx
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