Evaluate: `intcosx\/ (sqrt(4-sin^2x))\ dx`

Explanation

To evaluate the integral \( \int \frac{\cos x}{\sqrt{4 - \sin^2 x}} \, dx \), we will use a substitution method. Here’s a step-by-step solution:

### Step 1: Substitution
Let \( t = \sin x \). Then, we differentiate both sides with respect to \( x \):
\[ \frac{dt}{dx} = \cos x \implies dt = \cos x \, dx \]
This means that \( \cos x \, dx = dt \).
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