Download presentation
Published byAhmad Jarratt Modified over 3 years ago
1
4.6 Quick Graphs Using Slope-Intercept Form 1 GOAL
Graphing Using Slope-Intercept Form SLOPE-INTERCEPT FORM OF A LINEAR EQUATION The equation of a line with slope m and y-intercept b is: y = mx + b EXAMPLE 1
2
Extra Example 1 Write the equation 3x + 4y = 8 in slope-intercept form. Then identify the slope and the y-intercept. 3x + 4y = 8 Solve for y: y-intercept = 2 To graph a line using its slope and y-intercept, first plot the y-intercept, and then use the slope to graph at least one other point. EXAMPLE 2
3
Extra Example 2 Graph 2x + y = 5. (0, 5)
First, write in slope-intercept form: y = –2x + 5 Next, identify and plot the y-intercept: b = 5 Now use the slope to find another point and draw a line through the points:
4
In the coordinate plane, two vertical lines are parallel.
Two different lines in the same plane that do not intersect are _______. parallel In the coordinate plane, two vertical lines are parallel. Two nonvertical lines are parallel if and only if they have the same ______. slope EXAMPLE 3
5
Since equations a and c have the same slopes, they are parallel.
Extra Example 3 Which of the following lines are parallel? a. 3y = –9x – 5 b. 2y – 6x = –5 c. 12x + 4y = 1 Write each equation in slope-intercept form to determine their slopes: a. b. c. Since equations a and c have the same slopes, they are parallel.
6
Since each line has a slope of 2, they are parallel.
Checkpoint Are the lines –2x + y = 5 and 4y = 8x – 1 parallel? Since each line has a slope of 2, they are parallel.
7
4.6 Quick Graphs Using Slope-Intercept Form 2 GOAL
SOLVING REAL-LIFE PROBLEMS EXAMPLE 4
8
Extra Example 4 The equations below model the changing speeds of a car as it enters an expressway, travels on the expressway, and then exits the expressway. Create a graph to represent the car’s different speeds. Stage 1 (first 2 minutes): s = 15t Domain: 0 ≤ t < 2 Stage 2 (next 10 minutes): s = 55 Domain: 2 ≤ t < 12 Stage 3 (next 2 minutes): s = –15t Domain: 12 ≤ t < 14
9
Extra Example 4 (cont.) Stage 1 (first 2 minutes): s = 15t Domain: 0 ≤ t < 2 Stage 2 (next 10 minutes): s = 55 Domain: 2 ≤ t < 12 Stage 3 (next 2 minutes): s = –15t Domain: 12 ≤ t < 14 (2, 55) (12, 55) Speed (mi/h) Time (min) 60 50 40 30 20 10 (14, 25) (0, 25)
10
Checkpoint Graph each line for the given domain on the same coordinate axes. a. y = 2x Domain: –5 ≤ x < –3 b. y = 4 Domain: –3 ≤ x < –1 c. y = –4x Domain: –1 ≤ x < 0 y x
Similar presentations
© 2018 SlidePlayer.com Inc.
All rights reserved.
Ppt on sound navigation and ranging systemic Run ppt on raspberry pi Ppt on sea level rise graph Ppt on high court of india Ppt on question tags grammar Ppt on data handling for class 10 Ppt on advancement in science and technology Ppt on bluetooth with slides Ppt on any topic of maths for class 9 Ppt on revolt of 1857 images