Presentation on theme: "Quick Graphs Using Slope-Intercept Form"— Presentation transcript:
1 Quick Graphs Using Slope-Intercept Form Algebra 1 Section 4.6Quick Graphs Using Slope-Intercept Form
2 Important!!!This is a big concept in Algebra 1. You need to thoroughly understand this!Slope – Intercept Formy = mx + bm represents the slopeb represents the y-intercept
3 Writing EquationsWhen asked to write an equation, you need to know two things – slope (m) and y-intercept (b).
4 Example 1: Writing Equations Write an equation in slope-intercept form of the line that has a slope of 2 and a y-intercept of 6.To write an equation, you need two things:slope (m) =y – intercept (b) =We have both!! Plug them into slope-intercept formy = mx + by = 2x + 626
5 Writing EquationsWrite an equation in slope-intercept form for the following:
6 y = -3x – 4 y = -4x – 3 y = -3x + 4 y = -4x + 3 Write the equation of a line that has a y-intercept of -3 and a slope of -4.y = -3x – 4y = -4x – 3y = -3x + 4y = -4x + 3
7 To find the slope and y-intercept of an equation, write the equation in slope-intercept form: y = mx + b.Find the slope and y-intercept.y = 3x – 7y = mx + bm = 3, b = -7
8 Find the slope and y-intercept. 2) y = xy = mx + by = x + 03) y = 5y = 0x + 5m =b = 0m = 0b = 5
9 Find the slope and y-intercept. 4) 5x - 3y = 6 m =b = -2
10 Find the slope and y-intercept. 5) 2y + 2 = 4x Write it in slope-intercept form.(y = mx + b)2y + 2 = 4x2y = 4x – 2y = 2x - 1m = 2b = -1
11 Find the slope and y-intercept of y = -2x + 4 m = 2; b = 4m = 4; b = 2m = -2; b = 4m = 4; b = -2
12 Example 2: Graphing Using Slope and y-Intercept When given an equation, you can easily graph it in slope-intercept form. All you need is two things– the slope (m) and y-intercept (b).
13 Graphing Using Slope and y-intercept Step 1: Make sure the equation is in slope-intercept formStep 2: Find the slope and y- interceptStep 3: Plot the y-interceptStep 4: Apply the slope (rise/run) to the y-intercept
14 Review: Graphing with slope-intercept -31-3Start by graphing the y-intercept (b = 2).From the y-intercept, apply “rise over run” using your slope. rise = 1, run = -3Repeat this again from your new point.Draw a line through your points.1Start here
15 Graph: Step 1: y=mx+b Step 2: slope = 2 y-intercept = 3 Step 3: plot the y-intercept on a graphStep 4: apply the slope