Thursday
October 30, 2014

Homework Help: math

Posted by shan on Saturday, September 6, 2008 at 4:04pm.

tanx+secx=2cosx
(sinx/cosx)+ (1/cosx)=2cosx
(sinx+1)/cosx =2cosx
multiplying both sides by cosx
sinx + 1 =2cos^2x
sinx+1 = 2(1-sin^2x)
2sin^2x + sinx-1=0
(2sinx+1)(sinx-1)=0
x=30 x=270
but if i plug 270 back into the original equation i get undefined because tan 270 is undefined where did i go wrong?

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