Completing the square
Completing the square of a
quadratic equation.
Let’s study
together!
example 1.
Parrot
e d i t i o n.
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You were asked to
complete the square of this
quadratic equation:
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So we put
the equation
into our
table.
1
2
3
4
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Highlight the part
of the equation
that contain
x2 and x only.
1
2
Do not
highlight the
constant!
3
4
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Call this
expression : p
1
2
3
4
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Rewrite 6x as
(2)(3) x
1
2
3
4
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1
2
3
4
We need to do this to apply the formula :
2
2
2
a b
a
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2ab b
7

Rewrite 6x
a=x
(2)(3) x.
b=3
1
as
2
3
4
We need to do this to apply the formula :
a b
2
a
2
2ab b
2
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1
2
3
Add 32 to p.
4
a b
2
a
2
2ab b
2
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Add 32 to p.
1
2
3
Call this
expression : q
4
a b
2
a
2
2ab b
2
a=x
b=3
Now we can apply the above formula.
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a b
4
2
a2
2ab b 2
a=x
b=3
5
6
7
8
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a b
4
2
a2
2ab b 2
a=x
b=3
5
There! We applied
the formula.
6
7
8
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since
4
then
5
6
7
8
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4
since
5
then
6
7
8
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4
-9 + 5 is 4
5
6
Simplify y!
7
8
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Question :
Answer :
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Whew!! So tiring.
Now I can sleep.
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