The question asks: "On a graph, the value of a for a simple exponential function can be found at which coordinates?"

For a simple exponential function of the form $f(x) = a \cdot b^x$, the constant a represents the initial value of the function, which is the function's value when $x = 0$. This means that the point where the graph of the function crosses the y-axis is at $(0, a)$, since at $x = 0$, the function equals $f(0) = a$.

Therefore, the correct answer is:

• $(0, a)$

Would you like more details or have any questions? Here are five related questions to expand your understanding:

1. What does the base $b$ represent in an exponential function?
2. How does changing the value of a affect the graph of an exponential function?
3. What is the difference between exponential growth and decay?
4. How do you find the y-intercept of other types of functions, like quadratic or linear?
5. What is the horizontal asymptote of an exponential function, and how does it relate to a?

Tip: In an exponential function $f(x) = a \cdot b^x$, $a$ controls the vertical stretch or compression, while $b$ controls the growth or decay rate.