Evaluate the following integral: `int_0^(pi//4)tan^4x\ dx`

Explanation

To evaluate the integral \( \int_0^{\frac{\pi}{4}} \tan^4 x \, dx \), we can use the identity for \( \tan^2 x \) and some algebraic manipulation. Here’s the step-by-step solution:

### Step 1: Use the identity for \( \tan^2 x \)
We know that:
\[ \tan^2 x = \sec^2 x - 1 \]
Thus, we can express \( \tan^4 x \) as:
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