To find the value of the definite integral \(\int_0^{\frac{\pi}{2}} (-2 \cos x) \, dx\), we'll need to evaluate the integral and then substitute the limits of integration.

The integral of \(-2 \cos x\) with respect to \(x\) is given by:

\(\int -2 \cos x \, dx = -2 \int \cos x \, dx = -2 \sin x + C\)

Now, let's evaluate the definite integral using the limits of integration:

\(\int_0^{\frac{\pi}{2}} (-2 \cos x) \, dx = \left[-2 \sin x\right]_0^{\frac{\pi}{2}}\)

Substitute the upper and lower limits:

\(-2 \sin \left(\frac{\pi}{2}\right) - (-2 \sin 0) = -2 \cdot 1 - 0 = -2\)

So, the correct answer is option A: \(-2\).