Answer:
1) See attachment.
2a) Initial Amount = 3600.
Growth/Decay factor = ³/₂.
2b) Growth function.
4) 69 lions.
Explanation:
General form of an exponential function
where:
- x is the independent variable.
- y is the dependent variable.
- a is the initial value (y-intercept).
- b is the base (growth/decay factor) in decimal form.
If b > 1 then it is an increasing function.
If 0 < b < 1 then it is a decreasing function.
Question 1
Given function:
Complete the table of ordered pairs by substituting the values of x into the given function:
Plot the ordered pairs on the given coordinate plane (see attached graph) and draw a curve through them.
This exponential function has a horizonal asymptote at y = 0.
As the value of x approaches infinity, the function gets closer and closer to y = 0 (x-axis) but doesn't actually touch it.
Question 2
Given exponential function:
Part 2a
To find the initial amount "a" and growth/decay factor "b", simply compare the given function with the general exponential function.
Therefore:
- Initial Amount = 3600.
- Growth/Decay factor = ³/₂.
Part 2b
As b = ³/₂ and ³/₂ > 1, this is a growth function (increasing).
Question 3
"a" is the initial value (y-intercept) of an exponential function.
The y-intercept of a function is the y-value when x = 0.
Therefore, from inspection of the given table, the y-intercept of the given function is 1.
Therefore, a = 1.
"b" is the base (growth/decay factor) of an exponential function.
To find the base (growth/decay factor) of the given function, divide a value of y by its preceding value of y:
Therefore, b = 2.
So the exponential function for the given table is:
Question 4
If the population of lions started at 80, then the initial value "a" of the exponential function is 80.
If the population has been decreasing by 3.5% per year, then the population each year is 96.5% of the previous year since:
Therefore, the base "b" of the exponential function is 0.965 (in decimal form).
Substitute the found values of a and b into the exponential function formula to create an exponential function for the given scenario:
where:
- f(t) is the number of lions.
- t is the time (in years).
To find how many lions will there be in four years, substitute t = 4 into the found exponential equation:
Therefore, there will be 69 lions in four years.