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I am sorry to ask so many of these questions in such as short time span.

But how would I prove this following trigonometric identity. $$ \frac{1+\cos(2A)}{\sin(2A)}=\cot A $$ My work thus far is $$ \frac{1+\cos^2A-\sin^2A}{2\sin A\cos A} $$ I know $1-\sin^2A=\cos^2A$

So I do $$ \frac{\cos^2A+\cos^2A}{2\sin A\cos A} $$ I know not what I do next.

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    $\cos^2 A+\cos^2 A=2\cos^2 A$.2012-07-26
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    $\frac{cos^2A+cos^2A}{2\sin A\cos A}=\frac{2\cos^2A}{2\sin A \cos A}=\cot A$2012-07-26
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    There's also a nice way of seeing this. Take a look at [this answer](http://math.stackexchange.com/questions/120704/how-to-prove-a-trigonometric-identity/126075#126075) by robjohn.2012-07-26

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