1. Sept 4th
Learning outcome: To discover what happens
to a parabola’s graph when you change the
numbers in the equation?
 Launch:
 1. How would you change the equation
y = x2 to have the graph open down?
 2. How would you change the equation
y = x2 to have the graph move 6 units up?
 How would you change the equation
y = x2 to have the graph move 3 units right?

2. Explore: Graphing tool
Let’s try it:
http://www.cpm.org/flash/technology/tran
sform_parabolas.swf
Answer the following for y = a(x-h)2 + k
1. Which parameter (a, h or k) effects:
a. Orientation (up or down facing)
b. Shift up or down?
c. Shift left or right?

3. Explore: Predict
 1. For each equation, predict the vertex,
orientation (up or down), and whether it will
be a vertical stretch (narrower) or
compression (wider) of y = x2
 a. y = (x + 9) 2 b. y = x2
 c. y = 3x2 d. y = 1/3 (x-1)2
 e. y = -(x-7)2 +6 f. y = 2(x+3)2 - 8
 g. Check your predictions with a calculator
and describe how you need to change your
predictions

4. Explore: Graphing without a
calculator
 2. Graph each equation without making
a table or using a calculator. What are
your strategies?
 a. y = (x-7)2 – 2 b. y = 0.5 (x+3)2 + 1

5. Summary
 3. Now we are going to look at quadratics
in standard form y = ax2 +bx + c
 a. What is the orientation of y = 2x2 +4x -
30? (up or down facing)
 b. What is the stretch factor of y = 2x2 +4x -
30?
C. Can you look at =y = 2x2 +4x -30 and
figure out the vertex? (reminder of how:
vertex = -b/2a)