Which of the following functions represent exponential decay?

Option C: is the function that represent exponential decay.

Explanation:

The exponential decay can be represented by

where and

Option A:

From the function, we can see that and

Thus, and

Thus, the function does not represent exponential decay.

Hence, Option A is not the correct answer.

Option B:

From the function, we can see that and

Thus, and

Thus, the function does not represent exponential decay.

Hence, Option B is not the correct answer.

Option C:

From the function, we can see that and

Thus, and

Thus, the function represent exponential decay.

Hence, Option C is the correct answer.

Option D:

From the function, we can see that and

Thus, and

Thus, the function does not represent exponential decay.

Hence, Option D is not the correct answer.