Evaluate: `int_0^(pi//2)sin^4xdx`

Explanation

To evaluate the integral \( \int_0^{\frac{\pi}{2}} \sin^4 x \, dx \), we can follow these steps:

### Step 1: Rewrite \( \sin^4 x \)
We can express \( \sin^4 x \) as \( (\sin^2 x)^2 \). Thus, we have:
\[ \sin^4 x = (\sin^2 x)^2 \]

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