Answer:
Is nonlinear because the common ratio is 3
Explanation:
A linear function can be written as:
y = a*x + b
Where a is the slope and b is the y-intercept.
If this line passes through the points (x₁, y₁) and (x₂, y₂) then the slope is:
a = (y₂ - y₁)/(x₂ - x₁)
Now to this problem, if the data corresponds to a linear equation, then for any set of points we choose we should see the same slope.
For example, if we choose the first and second points:
(0,20) and (1, 60) the slope is:
a = (60 - 20)/(1 - 0) = 40/1 = 40
a = 40
Now if we choose the first and third points:
(0, 20) and (2, 180)
The slope is:
a = (180 - 20)/(2 - 0) = (160/2) = 80
So the slopes are different, which means that this function is nonlinear.
If we look at the f(x) values for the second point onwards, we can see that:
f(2) = 60
f(3) = 60*3 = 180
f(4) = 180*3 = 540
f(5) = 540*3 = 1620
and so on.
So this seems to be an exponential function with a common ratio of 3 between consecutive outputs.
Having a common ratio is not a property of linear functions, then the correct options is:
"Is nonlinear because the common ratio is 3"