Quick Graphs Using Slope-Intercept Form Algebra 1 Section 4.6 Quick Graphs Using Slope-Intercept Form

Important!!! This is a big concept in Algebra 1. You need to thoroughly understand this! Slope – Intercept Form y = mx + b m represents the slope b represents the y-intercept

Writing Equations When asked to write an equation, you need to know two things – slope (m) and y-intercept (b).

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 form y = mx + b y = 2x + 6 2 6

Writing Equations Write an equation in slope-intercept form for the following: 1. 3. 2. 4.

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 – 4 y = -4x – 3 y = -3x + 4 y = -4x + 3

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 – 7 y = mx + b m = 3, b = -7

Find the slope and y-intercept. 2) y = x y = mx + b y = x + 0 3) y = 5 y = 0x + 5 m = b = 0 m = 0 b = 5

Find the slope and y-intercept. 4) 5x - 3y = 6   m = b = -2

Find the slope and y-intercept. 5) 2y + 2 = 4x Write it in slope-intercept form. (y = mx + b) 2y + 2 = 4x - 2 - 2 2y = 4x – 2 2 2 2 y = 2x - 1 m = 2 b = -1

Find the slope and y-intercept of y = -2x + 4 m = 2; b = 4 m = 4; b = 2 m = -2; b = 4 m = 4; b = -2

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).

Graphing Using Slope and y-intercept Step 1: Make sure the equation is in slope-intercept form Step 2: Find the slope and y- intercept Step 3: Plot the y-intercept Step 4: Apply the slope (rise/run) to the y-intercept

Review: Graphing with slope-intercept -3 1 -3 Start by graphing the y-intercept (b = 2). From the y-intercept, apply “rise over run” using your slope. rise = 1, run = -3 Repeat this again from your new point. Draw a line through your points. 1 Start here

Graph: Step 1: y=mx+b Step 2: slope = 2 y-intercept = 3 Step 3: plot the y-intercept on a graph Step 4: apply the slope

Graph the following equations:

Homework: Complete Study Guide for Chapter 4  due Tuesday, November 19th