Unit 1: Linear Functions and Inequalities Day 2: Writing Equations of Lines and Graphing

Standard and Benchmark Recognize linear, quadratic, exponential and other common functions in real-world and mathematical situations; represent these functions with tables, verbal descriptions, symbols and graphs; solve problems involving these functions, and explain results in the original context.

Standard and Benchmark Sketch graphs of linear, quadratic and exponential functions, and translate between graphs, tables and symbolic representations. Know how to use graphing technology to graph these functions.

Learning Targets a) I can sketch the graph of a linear function b) I can write a linear function. c) I can translate between the graph, table, and equation of a linear function.

Day 2: Writing Equations of lines and Graphing Lines Recall from yesterday the slope-intercept form for an equation of a line: y = mx + b The slope intercept form can help us in two ways. 1) We can interpret it to graph a line 2) We can use it to write the equation of a line

Graphing a line Use the slope-intercept form to graph: a) b)

Writing Equations of Lines If we want to write the equation of a line having the graph, then we just need to do the work in reverse. Use the graph to find the slope (m) and y intercept (b) and then substitute them into the slope-intercept form WKST: Grape’s House

Grape’s House 1) Equation of AB 2) Equation of CB 3) Equation of DE 4) Equation of FG 5) Equation of HI

Writing equations of lines with real life situations that are linear Exploration: Backward Poet Divide into pairs and complete the situations on Backward Poet. Try to relate the information in the table and graph to what you know about equations of lines. Please note: WATCH the scaling used!!!!

Writing equations of lines with real life situations that are linear A closet organizer charges a $100 initial consultation fee plus $30 per hour. The cost as a function of the number of hours worked is graphed below What is the slope and its meaning? What is the y-intercept and what is its meaning? What is the equation to the line?

Writing equations of lines with real life situations that are linear A caterer charges a $200 fee plus $18 per person served. The cost as a function of the number of guests is shown in the graph. Write the equation to the line.

Work time: WKST: Borrow money WKST: Lesson 5-6 problem solving

Writing Equations of Lines Wrap up EXIT QUIZ 1) Write the equation in slope-intercept form. Then graph the line described by the equation. 6x + 2y = 10

Exit quiz cont. 2)