Name: ________________________
5.7 – Interpreting Graphs of Linear Functions
REVIEW:
A pizza company charges $10 for its medium no toppings pizza. For each topping,
you must pay an additional $1.25.
a) Graph the relation for up to 5 toppings.
b) Is this relation discrete or continuous?
c) What is the domain and range of this relation?
d) Is this relation a FUNCTION? Is it a linear relation?
e) If this is a linear function, state the rate of change of the linear function?
f) Create an equation for the relation. (Make sure you state what your variables
represent.)
A linear relation is any graph that forms a straight line. Any graph of a line that
is not vertical can also be called a __________________________.
Each graph below shows the temperature (T in degrees Celsius), as a function of
time (t in hours), for two locations.
The domain is: __________________
The domain is: ____________________
The range is: ___________________
The range is: _____________________
The rate of change is:
The rate of change is:
The rate of change is positive because the
The rate of change is negative because
temperature is _____________________
the temperature is __________________
over time.
over time.
KEY WORDS:
The x-coordinate of the point where a graph intersects the x-axis is called the
____________________ or _____________________________________.
The y-coordinate of the point where a graph intersects the y-axis is called the
___________________ or ______________________________________.
Name: ________________________
Point where graph intersects x-axis ________
Point where graph intersects x-axis _______
X-Intercept ______
X-Intercept ________
This point means:
This point means:
Point where graph intersects y-axis ________
Point where graph intersects y-axis _______
Y-Intercept __________
Y-Intercept ________
This point means:
This point means:
Example 1:
This graph shows how the height of a burning candle changes with time.
a) Write the coordinates of the points where the graph intersects the axes. Determine the
vertical and horizontal intercepts. Describe what the points of intersection represent.
b) What are the domain and range of this function? Are there any restrictions on the
domain & range?
Key Idea:
We can use x & y intercepts to graph a linear function written in function notation.
-
To determine the y-intercept, evaluate f(x) when x = 0. (In other words, find f(0).
-
To determine the x-intercept, determine the value of x when f(x) = 0.
Example 2:
Sketch a graph of each linear function:
a) f(x) = 4x – 3
What other strategy could you use to graph the
function?
b) f(x) = -2x + 7
Which strategy would be more efficient?
Name: ________________________
Example 3:
Which graph has a rate of change of –5 and a vertical intercept of 100?
Justify your answer.
a)
b)
Example 4:
This graph shows the total cost for a house call
by an electrician for up to 6 h work.
The electrician charges $190 to complete a job.
For how many hours did she work?
Assignment: page 319-323 #4, 5, 6(use grid paper), 8-10, 12.
QUIZ TOMORROW