Answer:
1. The required function is
.
2. The required function is
.
3. The required function is
.
Explanation:
1.
The exponential function is defined as

Where, a is initial value and b is growth rate.
The y-intercept of the given graph is (0,16) and the graph shows a decreasing function. So, the initial value is 16 and growth rate is less than 1.
The required function is

2.
The y-intercept of the function is (0,-3).
The line is passing through (0,-3) and (4,2). The slope of the line is

The slope intercept form of a line is

Where, m is slope and b is y-intercept.
The required function is

3.
The exponential function is defined as

Where, a is initial value and b is growth rate.
The y-intercept of the given graph is (0,3) and the graph shows a increasing function. So, the initial value is 3 and growth rate is greater than 1.
The required function is
