Cornell Notes
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Name: ___________________________________
Topic: 4.6 Completing the Square
Date: _10/3/2016__________________________
Class: _Algebra 2 ______
Essential Question: How do you solve quadratic equations by Completing the
Square?
Questions/Main Ideas:
Notes:
Solving by finding square 4x^2 + 10 = 46
roots
4x^2 = 36
X^2 = 9
X = +/- 3
3x^2 – 5 = 25
3X^2 = 30
x^2 = 10 ___
x = + or - /10
Perfect Square Trinomial X^2 + 4x + 4 = 25
(x+2) ^ 2 = 25
X+2 = +/- 5
X+2 = 5
x+2 = -5
X=3
x = -7
Completing the Square
Given x^2 + bx + c
=0
-c
-c
x^2 + bx
= -c
x^2 + bx + (b/2)^2 = -c + (b/2)^2
*
(x + b/2) ^2
= -c + (b/2)^2
__________
X + b/2
= + or - / -c + (b/2)^2
_________
X = -b + or - / (b/2)^2 – c
Completing the Square
to write in Vertex form
Summary
At * above,
H = -b / 2,
add c – (b/2)^2 to both sides
k = c – (b/2)^2
Classwork: WB Section 4.6 P103-4 #2-36 Even