
Max S. answered 02/11/20
Math and Physics Tutor with a Passion for Teaching
The first important thing this question tells us it that f is linear. This means that it always looks like a straight line with no curves or breaks. It could be horizontal or angled, but it will always be a straight line so now we have to figure out what the angle, or slope, is.
They give us two values for the function: f(3) = 4, and f(8) = 4. This tells us that the points (3,4) and (8,4) are on our line. The equation for the slope of a line can be written as:
(y2 - y1)/(x2 - x1)
In our problem (x1,y1) = (3,4), and (x2,y2) = (8,4), so:
(y2 - y1)/(x2 - x1) = (4 - 4)/(8-3) = 0/5 = 0
A line with 0 slope is a horizontal line.