Question

The table below represents a linear function f(x) and the equation represents a function g(x):

X f(x)
-1 -12 g(x)
0 -6 g(x)=2x+6
1 0
Part A: Write a sentence to compare the slope of the two functions and show the steps you used to determine the slope of f(x) and g(x)
Part B: which function has a greater y-intercept? Justify answer

Answer 1

Part A: The slope of f(x) is three times as great as the slope of g(x).

Part B: The y-intercept of g(x) is 12 larger than the y-intercept of f(x).

In order to find these two answers, you need to find a model for f(x). You can do that by first finding the slope. The formula is below.

slope (m) = (y2 - y1)/(x2 - x1)

In this equation (x1, y1) is the first point and (x2, y2) is a second point. For this purpose, we'll pick (1, 0) and (0, -6)

slope (m) = (-6 - 0)/(0 - 1)

m = -6/-1

m = 6

Now we know that the slope is 6, which is 3 times as great as the first slope. Now to find the y-intercept, we can use either point and the slope in slope intercept form.

y = mx + b

0 = 6(1) + b

0 = 6 + b

-6 = b

So we know the y-intercept is -6, which is 12 less than the y-intercept of g(x).