Evaluate: `int1/(cosx-sinx)\ dx`

Explanation

To evaluate the integral \( \int \frac{1}{\cos x - \sin x} \, dx \), we can follow these steps:

### Step 1: Multiply and Divide by \( \sqrt{2} \)
We start by multiplying and dividing the integrand by \( \sqrt{2} \):
\[ \int \frac{1}{\cos x - \sin x} \, dx = \int \frac{\sqrt{2}}{\sqrt{2}(\cos x - \sin x)} \, dx \]

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