singaporestudent.com 1

Completing the square

Completing the square of a quadratic equation.

P a r r o t e d i t i o n.

Let’s study together!

example 1.

2singaporestudent.com

You were asked to complete the square of this quadratic equation:

3

1

2

3

4

singaporestudent.com

So we put the equation into our table.

4

1

2

3

4

singaporestudent.com

Highlight the part of the equation that contain x2 and x only.

Do not highlight the constant!

5

1

2

3

4

singaporestudent.com

Call this expression : p

6

1

2

3

4

singaporestudent.com

Rewrite 6x as (2)(3) x

7

We need to do this to apply the formula :

1

2

3

4

singaporestudent.com

222 2 bababa

8

1

2

3

4

singaporestudent.com

Rewrite 6x as (2)(3) x.

We need to do this to apply the formula :

222 2 bababa

a = xb = 3

9

1

2

3

4

singaporestudent.com

222 2 bababa

Add 32 to p.

10

1

2

3

4

singaporestudent.com

Add 32 to p.

222 2 bababa a = xb = 3

Now we can apply the above formula.

Call this expression : q

11

4

5

6

7

8

singaporestudent.com

222 2 bababa

a = xb = 3

12

4

5

6

7

8

singaporestudent.com

222 2 bababa

a = xb = 3

There! We applied the formula.

13

4

5

6

7

8

singaporestudent.com

since

then

14

4

5

6

7

8

singaporestudent.com

since

then

15

4

5

6

7

8

singaporestudent.com

-9 + 5 is 4

Simplify y!

singaporestudent.com 16

Question :

Answer :

singaporestudent.com 17

Whew!! So tiring.Now I can sleep.