ALGEBRA 2
Name:_________________________________ Date:_____________
Vocabulary:
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Quadratic Function:
y = ax2 + bx + c, a  0
Parabola: the graph of a quadratic function – “U shaped”
Vertex:
the lowest or highest point on the graph – “the turning point”
Axis of Symmetry: the vertical line through the vertex which the
parabola is symmetric over.
Standard Form of a Quadratic Function:
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a tells if the graph _____________ _____________or _____________ _____________.
o
If a is positive, the graph __________________ __________________.
o
If a is negative, the graph __________________ __________________.
To find the x-coordinate of the vertex, use ___________________.
Graphing a Quadratic Function in Standard Form:
1.
2.
3.
4.
5.
Find and plot the vertex.
Draw the axis of symmetry (dotted line).
Plot two more points on the same side of the axis of symmetry.
Use symmetry to plot the two corresponding points of those points in step 3.
Draw a parabola through the plotted points.
Examples: Graph.
1)
𝑦 = 2𝑥 2 − 8𝑥 + 6
Vertex: _____________
X
Y
2)
1
𝑦 = 𝑥2 − 1
2
Vertex: _____________
X
Y
3)
𝑦 = −3𝑥 2
Vertex: _____________
X
Y
4)
𝑦 = 𝑥 2 + 6𝑥 + 5
Vertex: _____________
X
Y
5)
𝑦 = −𝑥 2 − 2𝑥 + 1
Vertex: _____________
X
Y