Evaluate `lim_(xrarr0)(xtan4x)/(1-cos4x).`

Explanation

To evaluate the limit \( \lim_{x \to 0} \frac{x \tan(4x)}{1 - \cos(4x)} \), we can follow these steps:

### Step 1: Rewrite the limit
We start with the limit:
\[ \lim_{x \to 0} \frac{x \tan(4x)}{1 - \cos(4x)} \]

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