Download presentation

Published byChristiana Higgins Modified over 8 years ago

1
Drill #19 Determine the value of r so that a line through the points has the given slope: 1. ( 2 , r ) , ( -1 , 2 ) m = -½ Find the slope of the following lines. Determine whether they are parallel, perpendicular, or neither: 2. y = 3x – x + 2y = 6 y = -3x x = 1 – 6y

2
**Drill #20 Find the slope intercept form of the following lines:**

1. x + 2y = x + ½ y = 9 3. Find the slope intercept form of the line passing through (1, 3) with a slope of 2. (Write the equation in point-slope for and solve for y.)

3
**Drill #21 Identify which of the following lines are parallel:**

1. x + 2y = 6 y = - ½x + 2 4y = 3 – 2x 4x - 8y = -10 2. Write an equation in slope intercept form parallel to y = 2x – 1 and passing through the point (1, 2). 3. Write an equation in slope intercept form perpendicular to 3x – 2y = 3 and passing through the point (3, -2).

4
Drill #23 Find the slope of the following lines and then determine which are parallel: 1. y = 2x + 3 y – 3 = 3(x + 1) 2x – y = 1 3y = 6x + 4 y = 3 y = ¾ 2. Write an equation in slope intercept form parallel to y = ½ x – 1 and passing through the point (4, 6). 3. Write an equation in slope intercept form perpendicular to y = ½ x – 1 and passing through the point (4, 6).

5
**2-4 Writing Linear Equations**

Objective: To write an equation of a line in slope intercept form given the slope and one or two points, and to write an equation of a line that is parallel or perpendicular to the graph of a given equation.

6
**Slope-Intercept Form Definition: An equation in the form of y = mx + b**

where m = slope and b = y- intercept In order to write an equation in slope-intercept form you need to know the slope (m) and the y- intercept (b)

7
**Classwork Use the Standard Form formulas: Y-intercept = C/B**

Slope = -A/B To complete 2-4 Practice #1-4

8
Classwork 2-4 Practice #9 – 17 (ODD)

9
**Writing Equations in Slope Intercept Form***

Write the equation of the line with given slope and y- intercepts: Ex1: m = 5 b = ¾ 1A: m = b = 1B: m = 0 b = 0

10
**Point Slope Form * Point Slope Form: An equation in the form of where**

Are the coordinates of a point on the line and m is the slope of the line. NOTE: For point slope form we need a point and the slope (or two points).

11
Point Slope Examples Find the equation of the line (in point-slope form): Ex2. m = 2 and passes through (2, -3) 2A. m = ½ and passes through (-2, 5)

12
**Find the Equation of a Line in Slope Intercept Form***

Passing through a point (x1, y1) with slope m: Method 1: 1. Substitute the point (x1, y1) and the slope m into the formula y = mx + b 2. Solve for b. 3. Substitute m and b into y = mx + b formula Method 2: 1. Write the equation in Point Slope form. 2. Solve for y

13
**Finding the equation of a line**

Find the slope-intercept form of a line that has a slope of and passes through (-6, 1). m = ? b = ? Method 1 Substitute m into the equation y = mx + b. Substitute (-6, 1) for x and y in the equation. Solve for b. Once you know m and b you can put the equation in slope-intercept form.

14
**Method 2: Point Slope to Slope Intecept**

Convert the point-slope equation into slope-intercept. To convert to slope-intercept form, solve the equation for y.

15
Classwork 2-4 Practice #9 – 17 (ODD)

16
**Write the Equation of a Parallel or Perpendicular Line***

1st Determine the slope of the line. If finding a parallel line use the same slope as the line If finding a perpendicular line use the negative reciprocal slope 2nd Write the equation in Point Slope form 3rd Convert to Standard or Slope-Intercept Form

17
**Find the equation of the line* EXAMPLE 1**

That passes through (-9, 5) and is perpendicular to the line whose equation is y = -3x + 2 Find the perpendicular slope Use the point (point- slope form) to find the equation of the line

18
**Parallel/Perpendicular Examples**

Find the equation of the line (in slope-intercept form): 1A. Parallel to y = 3x – 1 and passes through (2, -3) 1B. Perpendicular to 2x – y = 10 and passing through (-1, -2)

Similar presentations

© 2023 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google