Which function exhibits exponential decay for all ?
Answer and explanation
Correct answer: D.
- Step 1: An exponential function exhibits decay when and the base satisfies .
- Step 2: For , and , which satisfies , so it decays.
- Step 3: In contrast, grows because ; grows; has a negative base and is not an exponential function on the reals.
Answer
.
Why not the others: '' represents exponential growth; '' has a negative exponent making the effective base (growth); '' has an alternating signed base.
Practise more Functions, Logarithms and Exponential Models.
Free questions with an explanation for every one, and full timed EmSAT Achieve (UAE) mock tests.