1. Completing the Square and writing in Vertex Form
x2 + 8x -9 = 0
If you move the 25 back to the other side you will have it written in vertex form.
x2 + 8x = 9
(x+4)2 = 9
+16
(x+4)2 – 25 = 0
What is the Vertex?
(-4,-25)
y = (x + 4)2 – 25

2. y = x2 – 8x + 19
y = 5x2 + 10x + 7
y = x2 – 3x + 4
5x2 + 10x = -7
5(x2 + 2x) = -7
5(x + 1)2 =
y = 5(x + 1)2 + 2

3. Vertex form : ___________
Using this information how could we change from standard form to vertex form?
Practice f(x) = 2x2 – 4x + 1
y = 2(x – 1)2 - 1
Vertex form : ___________

4. The axis of symmetry is x = -b/2a The vertex is (-b/2a, f(-b/2a)
2. f(x) = x2 + 4x + 6
(-2,2)
Vertex: ______________
Axis of Symmetry: _________
Direction: __________
X = -2 UP
* Direction: If a is positive then UP if a is negative then DOWN. In this case a is 1 so up.
The axis of symmetry is x = -b/2a
The vertex is (-b/2a, f(-b/2a)

5. Ex 2. f(x) = x2 – 8x + 12 Vertex: ___(4,-4)________y O 5
Vertex: ___(4,-4)________
Axis of Symmetry: __x = 4____
Direction: __Up________
What about the y intercept?
How can we find it?
Same as always.
Min: -4
Domain: all real numbers
Range: [-4,∞)

6. Axis of Symmetry: ______ Direction: __________ Max or Min:_________
Practice f(x) = -2x2 + 6x + 2 x y O 5
Vertex: ___________
Axis of Symmetry: ______
Direction: __________
Max or Min:_________
Domain:
Range: