Download Unit 1: Linear Functions and Inequalities

Unit 1: Linear Functions and
Inequalities
Day 2: Writing Equations of Lines
and Graphing
Standard and Benchmark
9.2.2 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
9.2.2.3 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) y  2 x  5
b) 4 x  3 y  6
3
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)