Simplify
\[\frac{\sin x + \sin 2x}{1 + \cos x + \cos 2x}.\]
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Simplify
\[\frac{\sin x + \sin 2x}{1 + \cos x + \cos 2x}.\]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\tan x
Simplify
\[\frac{\sin x + \sin 2x}{1 + \cos x + \cos 2x}.\]
train