As a data analyst reviewing a baseline continuous growth model, you are examining the standard exponential function $f(x) = a^x$. According to the fundamental properties of this mathematical model, what is the equation of the horizontal line that the graph approaches but never touches or crosses?

A systems technician is using the standard exponential function $f(x) = a^x$ to model the gradual loss of pressure in a sealed chamber. True or False: According to the mathematical properties of this model, the graph representing the pressure will eventually touch or cross the $x$-axis (the line $y = 0$).

An electronics technician is documenting the discharge curve of a component, which is modeled by the standard exponential function $f(x) = a^x$. To ensure the technical manual is accurate, match the following mathematical terms with their correct descriptions or representations in the context of this graph.

Horizontal Asymptote of an Exponential Function

An operations analyst is using the standard exponential function $f(x) = a^x$ to model the residual value of specialized laboratory equipment over time. To establish the theoretical baseline for the equipment's value in the long-term forecast, the analyst must identify the horizontal asymptote of the graph. According to the properties of this function, the graph approaches but never touches the horizontal line defined by the equation $y =$ ____.