Tan(x+pi)-tan(pi-x)=2tan(x).

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Question from Steven, a student:

Verify the identity:
Tan(x+pi)-tan(pi-x)=2tan(x)

Hi Steven,

Use the fact that

\[\tan(a + b) = \frac{\tan(a) + \tan(b)}{1 - \tan(a) \tan(b)}\]

Penny

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