Graphing Lines

Page 1

Graphing Lines Graphing Lines Graphing linear equations is pretty simple, but only if you work neatly. If you're messy, you'll often make extra work for yourself, and you'll frequently get the wrong answer. I'll walk you through a few examples. Follow my pattern, and you should do fine. Graph y = 2x + 3 First, you draw what is called a "T-chart": it's a chart that looks a bit like the letter "T": The left column will contain the x-values that you will pick, and the right column will contain the corresponding y-values that you will compute. Label the columns: The first column will be where you choose your input (x) values; the second column is where you find the resulting output (y) values. Together, these make a point, (x, y). Pick some values for x. It's best to pick at least three value, to verify (when you're graphing) that you're getting a straight line. ("Linear" equations, the ones with just an x and a y, with no squared variables or square-rooted variables or any other fancy stuff, always graph as straight lines. That's where the name "linear" came from!) Know More About Central Limit Theorem Definition Math.Tutorvista.com

Page No. :- 1/5


Which x-values you pick is totally up to you! And it's perfectly okay if you pick values that are different from the book's choices, or different from your study partner's choices, or different from my choices. Some values may be more useful than others, but the choice is entirely up to you. Then your y-values will come from evaluating the equation at the x-values you've chosen. And the Tchart keeps the information all nice and neat. You can pick whatever values you like, but it's often best to "space them out" a bit. For instance, picking x = 1, 2, 3 might not give you as good a picture of your line as picking x = –3, 0, 3. That's not a rule, but it's often a helpful method. Once you've picked x-values, you have to compute the corresponding y-values: Some people like to add a third column to their T-chart to give room for a clear listing of the points that they've found: When graphing linear equations, "plugging in points" is a suggested method of solving the equations and putting them in a graphical format. To plug in points, select an x-coordinate (be reasonable in the number you select for the x-coordinate) and put the x-axis coordinate in the equation in place of x. Then solve the equation. This will give you a y-value. Put your chosen x-value and the y-value you solved for together, and you will have an ordered pair (a point) that you can graph. Repeat this process about 4 or 5 times and then connect the points you have graphed. The line you see will be the graph of a linear equation.

Learn More Probability Distributions

Math.Tutorvista.com

Page No. :- 2/5


Graphing Circles Graphing Circles Definition of Circle Graph A Circle Graph is a graph in the form of a circle that is divided into sectors, with each sector representing a part of a set of data. Example of Circle Graph In the example shown below, the circle graph shows the percentages of people who like different fruits. Each sector in the circle graph represents a separate percentage of people that like the respective fruit. A circle graph is a circular chart divided into sectors, illustrating proportion. In a pie chart, the arc length"> arc length of each sector and consequently its central angle and area, is proportional to the quantity it represents. When angles are measured with 1 turn as unit then a number of percent is identified with the same number of cent turns.

Math.Tutorvista.com

Page No. :- 3/5


Examples of Graphing Circle Example 1: In a college, there are 1200 students in first year, 2560 students in second year and 3210 students in third year. Draw a pie chart to represent the numbers of students in these groups. Solution: Total number of students = 1200+2560+3210 = 6970 In first year: size of angle = = 62 In second year: size of angle = = 132 In third year: size of angle = = 166 Draw the circle, measure in each sector. Label the each sector and the circle graph pie chart. Example 2 : In a college, there are 200 students in first year, 560 students in second year and 810 students in third year. Draw a pie chart to represent the numbers of students in these groups. Solution : Total number of students = 200+560+810 = 1570 In first year: size of angle = = 46 In second year: size of angle = = 128 In third year: size of angle = = 186 Draw the circle, measure in each sector. Label the each sector and the circle graph pie chart Read More About Weighted Averages Math.Tutorvista.com

Page No. :- 4/5


Thank You

Math.TutorVista.com


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.