Find minimum value of 2cos x + 2cos y

To find the minimum value of the equation 2cos x + 2cos y, we need to determine the range of values that cos x and cos y can take.

The range of the cosine function is -1 to 1. Therefore, the minimum value of 2cos x will be -2 and the minimum value of 2cos y will also be -2.

So, the minimum value of 2cos x + 2cos y = -2 + (-2) = -4.

Thus, the minimum value of the equation is -4.