b What happens if you put money in a bank account with interest?
A
aStarting point: 20 Multiplier: 1.06
Diagram:
B
b See solution.
Practice makes perfect
a In an exponential function y=ab^x, the coefficient a is the starting point and b is the multiplier. Examining the given function, we can identify the starting point and multiplier.
To draw the exponential function we need to find some ordered pairs through which its graph passes.
x
20(1.06)^x
y
-4
20(1.06)^(- 4)
15.8
-3
20(1.06)^(- 3)
16.8
-2
20(1.06)^(- 2)
17.8
-1
20(1.06)^(-1)
18.9
0
20(1.06)^0
20
1
20(1.06)^1
21.2
2
20(1.06)^2
22.5
3
20(1.06)^3
23.8
4
20(1.06)^4
25.2
Now we can draw the function.
b Let's think of one example of what this function could represent. It could describe the amount of money in a bank account if the annual interest is 0.06 and the amount of money initially put in the bank is $20.
