Interpreting and finding intercepts of linear functions

The  exercise appears under the 8th Grade Math Mission. This exercise finds axis intercepts in various contextual word problems.

Types of Problems
There are two types of problems in this exercise:


 * 1) Find the x-intercept word problem: This problem has a word problem that is asking about when something happens. The student needs to use the information in the problem to find the x-intercept of the model of the situation.Iafiolf1.png
 * 2) Find the y-intercept word problem: This problem has a word problem that is asking about an initial value. The student needs to use the information in the problem to find the y-intercept of the model of the situation.Iafiolf2.png

Strategies
Being able to find the equation of a line from two points and an ability to read English and translate into mathematics would ensure success on this exercise.
 * 1) Watching the words can help to determine which problem it is. When you are looking for where things began, it is often y-intercept, when you are looking for when they happen, it is often x.

Calculator Program for TI83/84 series
This program will provide the x-intercept and y-intercept of a line by providing two points (A,B) and (C,D).


 * Prompt A,B,C,D
 * (D-B)/(C-A)>M
 * Y-MX>B
 * (Y-B)/M>X
 * Disp X,B

Real-life applications

 * 1) Indicators from ETS show that the "New SAT" coming in 2015-2016 will have problems like this exercise.