A25­3Notes.notebook
February 02, 2015
Quadratic Functions
Algebra 2
Ch.5 Notes Page 18
Parent Function y = x2
P18 5­3 Transforming Parabolas
Reflection in x­axis
y = ­x2
Stretch (a > 1)
y = ax2
Shrink (0 < a < 1)
(by a factor of a)
Reflection in x­axis
Aug 19­6:20 AM
Vertex Form
y = a (x ­ h)2 + k
h is a horizontal shift / k is a vertical shift
Vertex is at (h, k)
Axis (Line) of Symmetry is at x = h
y = 3(x ­ 2)2 + 5
h shifts it to the Right 2.
k shifts it Up 5.
a means it is stretched.
Vertex is at (2, 5)
Line of Symm is at x = 2
Oct 8­7:09 AM
y = ­ax2
Sep 22­9:21 AM
Using Vertex Form to Graph
y = 2(x + 1)2 ­ 4
h is ­1 because the formula is (x ­ h)
h shifts it to the left 1.
k shifts it down 4.
a means it is stretched.
Line of Symm is at x = ­1
Vertex is at (­1, ­4)
Find another point and reflect it over Line of Symm.
x = 0
y = ? ­2
Oct 9­8:58 AM
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A25­3Notes.notebook
February 02, 2015
Practice Graphing Vertex Form
y = ­3(x + 2)2 + 4
Converting to Vertex Form
y = 2x2 + 10x + 7
1. Find Vertex
2. Substitute a, h, and k into the formula
a = Opens Down/Stretched
h = ­2
k = 4
Line of Symm is x = ­2
Vertex is at (­2, 4)
Substitute and Find 1 extra point.
Sketch the Parabola
Find another point and reflect it over Line of Symm.
x = 0
y = ? ­8
Oct 8­7:09 AM
Convert from Vertex to Standard
Oct 8­8:35 AM
HW #18
5­3 P255 #1,4,9,14,16,19,25­27,34,42bcd,47,53
Please put your name and class period at the top of the homework. Also include the homework number.
Feb 26­1:52 PM
Aug 19­6:25 AM
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