2. Quadratic Function
(y = ax2 + bx + c)
a, b, and c are called
the coefficients.
The graph will form a
parabola.
Each graph will have
either a maximum or
minimum point.
There is a line of
symmetry which will
divide the graph into
two halves.
3. y = x2
a = 1, b = 0, c = 0
Minimum point (0,0)
Axis of symmetry
x=0
y=x 2
4. What happen if we change the
value of a and c ?
y=3x2
y=-3x2
y=4x2+3
y=-4x2-2
5. Conclusion
(y = ax2+bx+c)
When a is positive,
When a is negative
When c is positive
When c is negative
the graph opens up
the graph opens
down
the graph moves up.
the graph moves
down.
6. Solving Quadratic Functions
(ax2 + bx + c = 0)
Since y = ax2 + bx +c , by setting y=0
we set up a quadratic equation.
To find the solutions means we need to
find the x-intercept.
Since the graph is a parabola, there will
be two solutions.
7. To solve quadratic equations
(graphing method)
X 2 - 2x = 0
To solve the
equation, put y = x2-x
into your calculator.
Find the x intercept.
Two solutions, x=0
and x=2.
y=x2-2x
9. Observations
Sometimes there are two solutions.
Sometimes there is only one solution.
Sometimes it is hard to locate the
solutions.
Sometimes there is no solution at all.