Handson Activity Competition Time Matching SlopeIntercept Form Graph

Hands-on Activity: Competition Time • Matching: Slope-Intercept Form & Graph

Home-Learning Assignment #3 - Review

Name: Date: Period: Topic: 1. Point-Slope Form 2. Standard Form Essential Question: What can be used to write and graph the equation of a line? Which form would better help me graph & write linear equations? Quick Review: What we Know so far…. Slope Intercept Form Where m is the slope and b is the intercept

Previously you learned one strategy for writing a linear equation when given the slope and a point on the line. . In this lesson you will learn a different strategy – one that uses the point-slope form of an equation of a line Objective: By the end of today’s class you will be able to write and graph linear equations using point-slope form

The New Stuff… Point- Slope Form Point- Slope form is: Where m is the slope and (x 1, y 1) is the given point

Example #1 Write the equation of the line that goes through the point (2, – 3) and has a slope of 4. Point = (2, – 3) Slope = 4 Starting with the point – slope form y – y 1 = m (x – x 1) Plug in the y-value, the slope, and the x-value to get y + 3 = 4 (x – 2) Notice, that when you replaced the “y 1” it became “+3”.

Write the Equation in Point-Slope Form Step 1: Plug it in

What is the graph of y – 1 = (x – 2)? 5 4 3 2 1 -5 -4 -3 -2 -1 1 -1 -2 -3 -4 -5 2 3 4 5

? ? ? Using two points to write an equation in point-slope form Can you write the equation of a line in point-slope form that passes through (-3, 6) and (1, -2)

? ? ? Using two points to write an equation in point-slope form 5 4 3 2 1 -5 -4 -3 -2 -1 -1 -2 -3 -4 -5 (2, 2) 1 2 3 (0, -3) 4 5

Standard Form Ax + By = C

The word “intercept” means to cross. x-intercept - the point (ordered pair) where a line crosses the x-axis. y-intercept - the point (ordered pair) where a line crosses the y-axis.

Using Standard Form: To find an intercept, set the other variable equal to zero. Ax + By = C 3 x – 5 y = 15

Your Turn (Find x & y-intercept): 1) 3 x + 4 y = 24 2) 7 x + 8 y = 21

Graph using X & Y-intercepts: 1) 3 x + 4 y = 24 2) 7 x + 8 y = 21

Graphing Horizontal Lines: § Slope is zero. § Equation form is y = #. a) y = -2 b) y=3 c) y=1

Graphing Vertical Lines: § Slope is undefined. § Equation form is x = #. a) x = -1 b) x=3 c) x=4

Transforming to Standard Form (Ax + By = C): y = 3 x + 4 y = 3/7 x + 4 y – 2 = - 1/3(x + 6)

Making the connection: How can I write the following point-slope form in slope-intercept form? y + 3 = 4 (x – 2) How can I write the following standard form in slope-intercept form? -4 x + y = - 11

Practice: Page 316 -318 (2 -6, 12, 35) Page 323 (6)

Review for Exam #4

Wrap-Up: • Vocabulary & Forms Review HLA #4: Point-Slope Form & Standard Form Page 316 – 318 (14, 16, 39) Page 324 (12, 14)