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Introductory Algebra
Glossary
Chapter Ten
quadratic equation
A quadratic equation is an
equation that can be written in the
form ax2 + bx + c = 0, where a, b,
and c are real numbers,
with a 0.
discriminant
The quantity under the radical in the
quadratic formula, b2 - 4ac.
complex number
Any number that can be written in
the form a + bi, where a and b are
real numbers.
imaginary number
A complex number a + bi
with b  0.
real part
The real part of a complex
number a + bi is a.
imaginary part
The imaginary part of the
complex number a + bi is b.
standard form of a complex
number
The standard form of a
complex number is a + bi.
conjugate of a complex
number
The conjugate of a complex
number a + bi is a - bi.
parabola
The graph of a second-degree
(quadratic) equation in two
variables is called a parabola.
parabola
The graph of a second-degree
(quadratic) equation in two
variables is called a parabola.
axis (axis of symmetry)
The axis of a parabola is the
vertical or horizontal line through
the vertex of the parabola.
quadratic function
A function defined by an equation of
the form f(x) = ax2 + bx + c, for
real numbers a, b, and c, with a 0.
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Introductory Algebra
Created by
James Q. Jacobs
Superstition Mountain Campus
Central Arizona College