1. (Free to use. May not be sold)
Year 12 - General
Quadratic Functions
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© G Dear 2009
(Free to use. May not be sold) 1

2. Quadratic Functions (1/6)
The independent variable has a power of 2.
The dependent variable has a power of 1.
y = ax2 + bx +c 1 1
When graphed they appear as a parabolic graph. 2

3. Quadratic Function y = x2 (2/6)-3 -2 -1 -½ 1 2 3 y 9 4 1 1 4 9 9 7 5 3 1 2 -1 -2 -3 x y
y=x2
Parabola 3

4. Quadratic Function y = x2 (3/6)-3 -2 -1 1 2 3 y 9 4 1 1 4 9
In this course we don’t use negative values for x. 4

5. Quadratic Function y = x2 (3/6)1 2 3 y 1 4 9 9 7 5 3 1 2 x y
y=x2 5

6. Quadratic Function y = 2x2 - 4x + 5 (4/6)1 2 3 4 y 5 3 5 11 21 20 16 12 8 4 1 2 3 x y
y=2x2-4x+5 6

7. Quadratic Function y = -x2 + 3x + 5 (5/6)1 2 3 4 y 5 7 7 5 1 10 8 6 4 2 1 3 x y
y=-x2+3x+5 7

8. Quadratic Function h = 20t – 5t2 (6/6)
Throwing a ball vertically
h = ut + ½at2
What is the maximum height? t 1 2 3 4 h 15 20 15 20 20 16 12 8 4 1 2 3 t h
h=20t-5t2 8