Hard Work Math

Hard Work Math

Chapter 3 Overview

Note: Most of this is copied word for word from www.purplemath.com or your textbook.
 
[pic]
Question: Graph the equation and then identify the Y-intercept AKA Graph linear equations of the type y = mx + b and Ax + By = C, identifying the y-intercept.
Part 1: Graph the equation
The first thing you need to do is draw what is called a "T-chart". It looks like this (that’s a random equation in the t-chart):
      [pic]
    • Replace x with a given value. They didn’t give you a value, so you can pick one. I generally pick -3, -2, -1, 0, 1, 2, 3.   These are small numbers, easy to work with, and run through the center of the graph.
    • Solve the equation for the numbers that you selected. (This is a random example equation).
      [pic]
Some people like to add a third column, in which they write down what the actual plot-points are, like this:
      [pic]
The x-coordinate (the number for the x-axis) always comes first. The first number (the first coordinate) is always on the horizontal axis.
Plot your points.
How to plot a point:
|So, for the point (5, 2), you would start at the       |[pic]                                         |
|"origin", the spot where the axes cross:               |                                               |
|...then count over to "five" on the x-axis:             |[pic]                                         |
|...then count up to "two", moving parallel to the       |[pic]                                         |
|y-axis:                                                 |                                               |
|...and then draw in the dot:                           |[pic]                                         |

Finding the location of (5, 2) and then drawing its dot is called "plotting the point (5, 2)".
When plotting, remember that the first number is for the horizontal axis and the second number is for the vertical axis. You always go "so far over or back" and then "so far up or down"...