Step 1: Use the identity \( \sin^2 x = \frac{1 - \cos 2x}{2} \).
Step 2: Substitute this identity into the integral:
\[
\int \sin^2 x \, dx = \int \frac{1 - \cos 2x}{2} \, dx
\]
Step 3: Integrate each term separately:
\[
\int \frac{1}{2} \, dx = \frac{x}{2}, \quad \int \frac{\cos 2x}{2} \, dx = \frac{\sin 2x}{4}
\]
Thus, the integral is:
\[
\frac{x}{2} - \frac{\cos 2x}{2}.
\]
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