Think about this
situation. The graph
shows th e a ltitu d e
of the balloon with
respect to tim e. I t
doesn't show the
path of the balloon.
. M A T H E M A T I C A L
I P R A C T I C E S
| ' Getting Ready!
•ing it s linear
ep t f o rm? (Hint :
escent at x = 0 ?)
The red line shows t he alt it ude of a I
d escen t. W h at is an eq uat io n o f t h e I
What is the altitude of the balloon w
640
ai
— 600 <D
"O
3 560
640)
(35 580)
(45 560)
@ Common Core State Standards
F-LE.A.2 Co n st r u c t l i n e a r... f u n c t i o n s... g i v en a
graph, a description of a relationship, or two input-
output pairs. A lso A -C E D .A .2 , F-IF.B.4, F-IF.C.7a,
F-LE.B.5
M P 1, M P 3, M P 4
Objective To write an d g raph lin ear eq u atio n s using point-slope form
Point-Slope Form
20
Ti me
^ Lesson t
Vocabulary
point-slope form
You have learn ed how to w rite an eq u a tio n of a line by using its y-intercept. In this
lesson, you will learn how to w rite a n eq u a tio n without u s i n g t h e y - i n t e r c e p t.
Esse n t i a l U n d e r st a n d i n g You can use the slope of a line and any point on the line to
write and graph an equation of the line. Any two equations for the sam e line are equivalent.
Key Concep t Point-Slope Form of a Linear Equation
Definition Graph
The point-slope form of an equation of a
nonvertical line w ith slope m a n d through
point [xv y x) is y - y1 = m (x - x x).
Symbols
y - y x = m[x - Xj)
t f t
y-coordinate slope x-coordinate
y m _ riseru n /
y
V (*i\y)
X
0
When you use
y - y, = m(x - x,),
(xv y.|) represents
a specific point and
(x, y) represents
any point.
If PowerAlgebra.com ....j h; 3,1 5
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