260 likes | 270 Views
Learn to identify linear functions and write them in standard form. Understand how to find and graph the x-intercept and y-intercept. Practice comparing properties of linear functions.
E N D
Content Standards F.IF.4 For a function that models a relationship between two quantities, interpret key features of graphs and tables in terms of the quantities, and sketch graphs showing key features given a verbal description of the relationship. F.IF.9 Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). Mathematical Practices 3 Construct viable arguments and critique the reasoning of others. CCSS
You analyzed relations and functions. • Identify linear relations and functions. • Write linear equations in standard form. Then/Now
linear relation • nonlinear relation • linear equation • linear function • standard form • y-intercept • x-intercept Vocabulary
Identify Linear Functions A.State whether g(x) = 2x – 5 is a linear function. Write yes or no. Explain. Answer: Example 1A
Identify Linear Functions A.State whether g(x) = 2x – 5 is a linear function. Write yes or no. Explain. Answer: Yes; this is a linear function because it is in the form g(x) = mx + b; m = 2, b = –5. Example 1A
Identify Linear Functions B.State whether p(x) = x3 + 2 is a linear function. Write yes or no. Explain. Answer: Example 1B
Identify Linear Functions B.State whether p(x) = x3 + 2 is a linear function. Write yes or no. Explain. Answer: No; this is not a linear function because x has an exponent other than 1. Example 1B
A. State whether h(x) = 3x – 2 is a linear function. Explain. A. yes; m = –2, b = 3 B. yes; m = 3, b = –2 C. No; x has an exponent other than 1. D. No; there is no slope. Example 1A
A. State whether h(x) = 3x – 2 is a linear function. Explain. A. yes; m = –2, b = 3 B. yes; m = 3, b = –2 C. No; x has an exponent other than 1. D. No; there is no slope. Example 1A
B. State whether f(x) = x2 – 4 is a linear function. Explain. A. yes; m = 1, b = –4 B. yes; m = –4, b = 1 C. No; two variables are multiplied together. D. No; x has an exponent other than 1. Example 1B
B. State whether f(x) = x2 – 4 is a linear function. Explain. A. yes; m = 1, b = –4 B. yes; m = –4, b = 1 C. No; two variables are multiplied together. D. No; x has an exponent other than 1. Example 1B
C. State whether g(x, y) = 3xy is a linear function. Explain. A. yes; m = 3, b = 1 B. yes; m = 3, b = 0 C. No; two variables are multiplied together. D. No; x has an exponent other than 1. Example 1C
C. State whether g(x, y) = 3xy is a linear function. Explain. A. yes; m = 3, b = 1 B. yes; m = 3, b = 0 C. No; two variables are multiplied together. D. No; x has an exponent other than 1. Example 1C
A. 50 miles B. 5 miles C. 2 miles D. 0.5 miles Example 2A
A. 50 miles B. 5 miles C. 2 miles D. 0.5 miles Example 2A
Standard Form Write y = 3x – 9 in standard form. Identify A, B, and C. y = 3x – 9 Original equation –3x + y = –9 Subtract 3x from each side. 3x – y = 9 Multiply each side by –1 so that A≥ 0. Answer: Example 3
Standard Form Write y = 3x – 9 in standard form. Identify A, B, and C. y = 3x – 9 Original equation –3x + y = –9 Subtract 3x from each side. 3x – y = 9 Multiply each side by –1 so that A≥ 0. Answer: 3x – y = 9; A = 3, B = –1, and C = 9 Example 3
Write y = –2x + 5 in standard form. A.y = –2x + 5 B. –5 = –2x + y C. 2x+ y = 5 D. –2x– 5 = –y Example 3
Write y = –2x + 5 in standard form. A.y = –2x + 5 B. –5 = –2x + y C. 2x+ y = 5 D. –2x– 5 = –y Example 3
Use Intercepts to Graph a Line Find the x-intercept and the y-intercept of the graph of –2x + y – 4 = 0. Then graph the equation. The x-intercept is the value of x when y = 0. –2x + y– 4 = 0 Original equation –2x + 0– 4 = 0 Substitute 0 for y. –2x = 4 Add 4 to each side. x = –2 Divide each side by –2. The x-intercept is –2. The graph crosses the x-axis at (–2, 0). Example 4
Use Intercepts to Graph a Line Likewise, the y-intercept is the value of y when x = 0. –2x + y – 4 = 0 Original equation –2(0) + y – 4 = 0 Substitute 0 for x. y = 4 Add 4 to each side. The y-intercept is 4. The graph crosses the y-axis at (0, 4). Example 4
Use Intercepts to Graph a Line Use the ordered pairs to graph this equation. Answer: Example 4
Use Intercepts to Graph a Line Use the ordered pairs to graph this equation. Answer: The x-intercept is –2, and the y-intercept is 4. Example 4
What are the x-intercept and the y-intercept of the graph of 3x – y + 6 = 0? A.x-intercept = –2y-intercept = 6 B.x-intercept = 6y-intercept = –2 C.x-intercept = 2y-intercept = –6 D.x-intercept = –6y-intercept = 2 Example 4
What are the x-intercept and the y-intercept of the graph of 3x – y + 6 = 0? A.x-intercept = –2y-intercept = 6 B.x-intercept = 6y-intercept = –2 C.x-intercept = 2y-intercept = –6 D.x-intercept = –6y-intercept = 2 Example 4