We can sometimes use trigonometric identities to transform integrals. The integral formulas for `sin^(2)x and cos^(2)x` arise frequently in applications. Evaluate:
`intcos^(2)xdx`

Explanation

To evaluate the integral \( \int \cos^2 x \, dx \), we can use a trigonometric identity to simplify the expression. The identity we will use is:

\[ \cos^2 x = \frac{1 + \cos 2x}{2} \]

### Step-by-Step Solution:

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