Alex is deciding between two investment options, Option A and Option B. He wants to choose the option that has the highest rate of growth over the first 3 years, because he plans to withdraw his investment at that time. The growth of Option A and Option B can be modeled by their respective functions, A(x) and B(x), which follow.

Question

A(x)=5√2x+7

B(x)=2^x+9

Part A: What is the average rate of growth of A(x) for the first 3 years?

Part B: What is the average rate of growth of B(x) for the first 3 years?

Part C: Which option should Alex invest in? Why?

Select one answer for Part A, one answer for Part B, and one answer for Part C.

Answer 1

Part A: (A(3)-A(0))/(3-0)
Part B: (B(3)-B(0))/(3-0)
Since the denominators are the same, just compare the growth A and B over the interval.