abscissa: x-coordinate. The abscissa of the point (a, b) is a.
absolute value: the distance of a number from zero. The positive value.
acceleration: the rate of change of velocity. If position is represented
by s(t), then velocity
is s'(t) and acceleration is s"(t).
acute angle: a positive angle that measures less than 90 degrees.
acute triangle: a triangle each of whose angles measures less than 90 degrees.
additive identity: The number zero is called the additive identity because when you add it
to a number, N, the result you get is the same number, N.
additive inverse: the additive inverse of a number, N, is the number that when you add it
to N, the result that you get is zero. The additive inverse of 7 is -7.
The additive inverse of -3 is 3.
adjacent angles: two angles that share both a side and a vertex.
altitude: the perpendicular distance from the base of a figure to the highest point of the
figure.
amplitude: half the difference between the largest and smallest function value of a
periodic function.
angle: the union of two rays with a common endpoint.
antecedent: the hypothesis of conditional statement. The "if" part of an "if-then"
statement.
antiderivative: the antiderivative of a function, f(x), is a function, F(x), whose derivative is
f(x). Also called the indefinite integral.
apothem: the perpendicular distance from the center to a side of a regular polygon.
arc: the set of points on a circle that lie in the interior of a central angle.
arc length: s = integral (sqrt (1 + (dy/dx)2)) dx.
arccos: If x = cos y, then y = arccos x. The inverse of the cosine function.
arccsc: If x = csc y, then y = arccsc x. The inverse of the cosecant function.
arccot: If x = cot y, then y = arccot x. The inverse of the cotangent function.
arcsec: If x = sec y, then y = arcsec x. The inverse of the secant function.
arcsin: If x = sin y, then y = arcsin x. The inverse of the sine function.
arctan: If x = tan y, then y = arctan x. The inverse of the tangent function.
argument: The independent variable in a function.
arithmetic mean: The sum of a set of numbers divided by the number of numbers. Also
called the average.
arithmetic sequence: a sequence of numbers of the form
a, a + b, a + 2b, a + 3b, ... , a + (n - 1)b
arithmetic series: the sum of an arithmetic sequence.
associative property of addition: (a + b) + c = a + (b + c)
associative property of multiplication: (a * b) * c = a * (b * c)
asymptote: a straight line that is a close approximation to a curve as the curve goes off
to infinity.
average: same as arithmetic mean.
axiom: a statement that is assumed to be true without proof. Postulate.
axis of symmetry: a line that passes through a figure in such a way that the part of the
figure on one side of the line is a mirror reflection of the part of the
figure on the other side of the line.