Evaluate: `int(sin4x)/(sinx)\ dx`

Explanation

To evaluate the integral \( \int \frac{\sin 4x}{\sin x} \, dx \), we can follow these steps:

### Step 1: Rewrite \( \sin 4x \)
We can use the double angle identity for sine to express \( \sin 4x \):
\[ \sin 4x = 2 \sin 2x \cos 2x \]
Thus, we can rewrite the integral as:
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