The domain of a step function is all real numbers. The equation G(x) = -[x] + 3 can be expressed as G(x) = { -x for x < 0; 3 for x ≥ 0}. The domain of G(x) is all real numbers.
To explain further, a step function can be expressed as two separate equations, one for x < 0 and one for x ≥ 0. The equation for x < 0 is G(x) = -x and the equation for x ≥ 0 is G(x) = 3. The domain of G(x) is all real numbers. This means that any x value, whether it is greater than or less than 0, will be included in the domain of G(x).