Question

The graph shows how the number of gallons of water in abathtub changes as the tub is being filled.a. What is the slope of the line?b. How can you show that the slope of the line is constant?

Answer 1

a. What is the slope of the line?

The slope of the line in this case (using the points (1,4) and (2,8)) is:

$S=\frac{8-4}{2-1}=\frac{4}{1}=4$

That function moves 4 units up for each unit to the right.

b. How can you show that the slope of the line is constant?

We can see it because regardless of the points we take, it will always be the same. When graph the slope we can see that similar triangles are always obtained.