1 / 18

2 – 3: Quick Graphs of Linear Equations

2 – 3: Quick Graphs of Linear Equations. Objective: CA Standard 17: Use the slope – intercept form of a linear equation to graph a linear equation. Use the standard form of a Linear equation to graph linear equations.

myron
Télécharger la présentation

2 – 3: Quick Graphs of Linear Equations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2 – 3: Quick Graphs ofLinear Equations Objective: CA Standard 17: Use the slope – intercept form of a linear equation to graph a linear equation. Use the standard form of a Linear equation to graph linear equations.

  2. If the graph of an equation intercepts the y-axis at (0, b), then the number b is the y-intercept of the graph.

  3. Graphing equations in slope – intercept form. The slope intercept form of an equation gives you a quick way to graph the equation. Step 1. Write the equation in slope – intercept form by solving for y. Step 2. Find the y-intercept and use it to plot the point where the line crosses the y-axis. Step 3. Find the slope and use it to plot a second point on the line. Step 4. Draw a line through the two points.

  4. Example 1: Graphing with the Slope – intercept form. Step 1: Write the equation in slope – intercept form by solving for y.

  5. Step 2: Find the y-intercept and use it to plot the point where the line crosses the y-axis. The y-intercept is (0, -2). Plot (0, -2) Step 3: Find the slope and use it to plot a second point on the line. The slope is ¾. From the point (0, -2) go up 3 units and over to the right 4 units. (4, 1)

  6. Step 4: Draw a line through the two points (0, -2) and (4, 1).

  7. Standard Form of a Linear Equation The standard form of a linear equation is Ax + By = C where A and B are not both zeros.

  8. Graphing Equations in Standard Form The standard form of an equation gives you a quick way to graph the equation: Step 1: Write the equation in standard form. Step 2: Find the x-intercept by letting y = 0 and solving for x. Use the x-intercept to plot the point where the line crosses the x-axis.

  9. Step 3: Find the y-intercept by letting x = 0 and solving for y. Use the y-intercept to plot the point where the line crosses the y-axis. Step 4: Draw a line through the two points.

  10. Example 3: Draw Quick Graphs Graph 2x + 3y = 12 Step 1: The equation is already in standard form. Step 2: 2x +3y = 12, let y =0 2x + 3(0) = 12 2x =12 x = 6 The x-intercept is (6, 0)

  11. Step 3: 2(0) + 3y = 12, let x = 0 3y =12 y = 4 The y-intercept is (0, 4)

  12. Step 4: Plot the two points (6, 0) and (0, 4), then draw a line through them.

  13. Horizontal and Vertical Lines Horizontal Lines: The graph of y = c is a horizontal line through (0, c). Vertical Lines: The graph of x = c is a vertical line through (c, 0). C is a constant.

  14. HOMEWORK • P. 86 #25-35 Odd, #43-51 EOO

  15. Example 4: Graphing Horizontal and Vertical Lines Graph y = 3 and x = -2

  16. Example 2: Using the Slope – Intercept Form To buy a $ 1200 stereo, you pay a $200 dollar deposit and then make weekly payments according to the equation a = 1000 – 40t, where a is the amount you owe and t is the number of week. a. How much do you originally owe? 1200 – 200 = 1,000

  17. b. What are your weekly payments?

  18. c. Graph the model

More Related