Final Answer:
The horizontal asymptote of the function

Explanation;
In order to determine the horizontal asymptote of the given function
we need to analyze the behavior of the function as (x) approaches positive and negative infinity. The function
approaches zero as (x) goes to infinity, and since it is subtracted by 3, the overall function approaches
tends towards positive infinity. Mathematically, this can be expressed as:

Similarly as (x) goes to negative infinity
approaches infinity, but againsubtracting 3 from it results in the function approaching

![\[ \lim_{{x \to -\infty}} (e^(-x) - 3) = -3 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/x53km2uy6h800iwrhl2e8lc554v2sxtkr2.png)
Therefore, the horizontal asymptote of the function
. This means that as (x) becomes extremely large in either the positive or negative direction, the values of the function (
) will get arbitrarily close to (-3). The presence of the exponential
) ensures that the function approaches but never reaches (-3)resulting in a horizontal asymptote at (y = -3).