Question

(Q9) Decide if the function is an exponential growth function or exponential decay function, and describe its end behavior using limits. y=0.8^x

Answer 1

C

Explanation:

A function in the form
`y=a*b^x` is an exponential function. If

• a > 0, and b > 1 -- this is exponential growth function
• a > 0, and 0 < b < 1 -- this is exponential decay function

The given function can be written as
`y=1*0.8^x`, so a > 0 and 0 < b < 1, hence this is exponential decay function.

For end behavior, we take limits from -∞ and from ∞. If we do that we can see that C is the correct answer. Also, looking at the graph explains it. Attached is the graph.

From the graph, as we move towards negative infinity, the graph goes towards positive infinity and as we move towards positive infinity, the graph goes towards 0.