Question

A surf instructor has an initial fee of $12 and charges $8

per hour for lessons.
Explain how to determine what the y-intercept is and
where it would be located on the graph.

Answer 1

Sample Answer: The y-intercept in slope-intercept form is b, which is represented by 12. The y-intercept is the initial value, and is found on the graph as the point (0, 12) where the line crosses the y-axis.

Explanation:

Answer 2

Given:

A surf instructor has an initial fee of $12 and charges $8 per hour for lessons.

To find:

The y-intercept and its location on the graph.

Solution:

Initial fee = $12

Variable fee = $8 per hour.

Let the total fee be y for x hours. Then,

`y=12+8x`

Put x=0, to find the y-intercept.

`y=12+8(0)`

`y=12+0`

`y=12`

Therefore, the y-intercept is 12.

Table of values for
`y=12+8x`,

x y

0 12

-1 4

Plot (0,12) and (-1,4) on a coordinate plane and connect them by a straight line.

Clearly, the y-intercept is located at (0,12).