One relationship
is b e tw e e n th e
le n g th o f a shadow
and th e tim e o f
day.
MATHEMATICAL
PRACTICES
Patterns and
Linear Functions
@ Common Core State Standards
A-REI.D.10 Understand that the graph of an equation
in tw o variables is the set o f all its solutions plotted in
the coordinate plane, often fo rm in g a curve (which could
be a line). Also F-IF.B.4
M P 1, M P 2, MP 3, M P 4
Object ive T o i d e n t i f y a n d r e p r e s e n t p a t t e r n s t h a t d e s c r ib e l in e a r f u n c t io n s
Lesso n
Vocabulary
dependent
variable
in d e p e n d e n t
variable
in p u t
output
function
lin e a r fu n c tio n
I
In the Solve It, you identified variables whose value depends o n t h e v a lu e o f a n o t h e r v a r ia b le.
In a relationship betw een variables, the dependent variable changes in response to
another variable, the in d ep en d en t variable. Values of the independent variable are
called inputs. V a lu e s o f th e d e p e n d e n t v a r ia b le a re c a lle d outputs.
Esse n t i a l U n d e r st a n d i n g T h e v a lu e o f o n e v a r ia b le m a y b e u n i q u e ly
d e t e r m in e d b y th e v a lu e o f a n o t h e r v a r ia b le. S u c h r e la t io n s h ip s m a y b e r e p r e s e n te d
u s in g ta b le s , w o r d s , e q u a tio n s , se ts o f o r d e r e d p a ir s , a n d g ra p h s.
Rep r esen t i n g a Geo m et r i c Rel at i o n sh i p
In the diagram below, what is the relationship between the number of rectangles
and the perimeter of the figure they form? Represent this relationship using a
table, words, an equation, and a graph.
1 1 1 1 1 1111
1 rectang le 2 rectangles 3 rectangles 4 rectangles
240 Chapter 4 An Introduction to Functions