1 / 16

Y = mx + b

Y = mx + b. Equation of a line. Remember. The line y = mx + b is a straight line with slope m and y-intercept b . The value of m indicates the direction and steepness of a line. The value of b indicates where the graph intersects the y-axis. Take Note (page 107).

vian
Download Presentation

Y = mx + b

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. Y = mx + b Equation of a line

  2. Remember • The line y = mx + b is a straight line with slope m and y-intercept b. • The value of m indicates the direction and steepness of a line. • The value of b indicates where the graph intersects the y-axis.

  3. Take Note (page 107) • A horizontal line has an equation y = b, where b is the y-intercept. • A vertical line has equation x = a, where a is the x-intercept. • The equation y = mx, means the line passes through the origin (0,0). • EXAMPLE: Slope 3 means y/x or 3/1

  4. Use the formula for slope and count the spaces on a graph to solve for the slope of the line. YOU TRY

  5. Use the formula and count the spaces on a graph to solve for the slope of the line. SOLUTION RISE RUN Slope = -2 1 = m = -2

  6. Find the slope of a line when you are given two points on the line. YOU TRY Points on the line are: B(2,1), C(5,7)

  7. Find the slope of a line when you are given two points on the line. SOLUTION Points on the line are: B(2,1), C(5,7) Slope = y2 - y1 x2 - x1 ( 7 - 1) (5 - 2) = 6 3 = m = 2

  8. YOU TRY Use the following equation of the line to determine the slope of that line. Equation in Standard Form x - 2y - 8 = 0

  9. SOLUTION Use the following equation of the line to determine the slope of that line. Equation in Standard Form x - 2y - 8 = 0 -2y = -x + 8 -2y -2 -x -2 8 -2 = + 1 2 y = x - 4 Slope

  10. YOU TRY Find the equation of the line when you are given the slope and the y-intercept. m = 3, b = -3

  11. SOLUTION Find the equation of the line when you are given the slope and the y-intercept. m = 3, b = -3 Slope y-intercept form for equation of a line. y = mx + b y = 3x -3

  12. Find the equation of the line when you are given the slope and one point on the line. YOU TRY m = 3, A(2,5) Step 2: Find the y-intercept Step 3: Find equation of line Standard form y = mx +b Step 1: Graph

  13. Find the equation of the line when you are given the slope and one point on the line. SOLUTION m = 3, A(2,5) Find y -int. Plug numbers into y = mx + b y = mx + b 5 = (3)(2) + b 5 = 6 + b 5 - 6 = b - 1 = b y = mx + b y = 3x - 1

  14. Find the equation of the line when you are given two points on the line. YOU TRY A(-1,5) , B(2,-1) Step 2: Find slope Step 3: Find y -intercept Step 1: Graph Step 4: Find equation (Standard form y = mx + b)

  15. Find the equation of the line when you are given two points on the line. SOLUTION A(-1,5) , B(2,-1) Find slope Find y -intercept. y2 - y1 x2 - x1 y = mx + b 5 = (-2)(-1) + b 5 = 2 + b 5 - 2 = b 3 = b (5 - (-1)) (-1 - 2) = 6 -3 = Find equation. = -2 y = -2x +3

  16. Class Work • Complete the “YOU TRY” questions in this lesson and bring them to me when finished. • Finish Lesson 10 worksheet if not done. • Check solutions to Lesson 10 • Do Lesson 10(2) worksheet

More Related