diagonal (dye-AG-uh-nuhl) A line segment that
connects two nonadjacent vertices of a polygon.
(p. 253)
diameter (dye-AM-uh-tur) A chord that passes
through the center of a circle. (p. 262)
dilation (dye-LAY-shuhn) A transformation that
reduces or enlarges the size of a figure. (p. 374)
dimensional analysis (duh-MEN-shuhn-uhl uh-
NAL-uh-sis) The conversion from one unit
system to another. (p. 166)
direct proportion(duh-REKT pruh-POR-shuhn)
A relationship in which an increase or decrease
in one quantity causes the same kind of change in
the other quantify. (p. 154)
direct variation (duh-REKT vair-ee-AY-shuhn) A
linear function in which the output (the y-value)
is directly proportional to the input (the x-value),
thus making the quotient the same for any
ordered-pair solution.
y kx or k, where x, k 0. (p. 364)
discount(DISS-kownt) The amount by which the
regular or list price of an item is reduced. (p. 194)
discount rate (DISS-kownt RAYT) The ratio that
represents the percent decrease in the list price.
(p. 194)
disjoint events (diss-JOYNT i-VENTS) Two
events that have no outcomes in common. Also
called mutually exclusive events. (p. 335)
Distributive Property of Multiplication over
Addition(diss-TRIB-yoo-tive PROP-ur-tee
UHV muhl-tuh-pluh-KAY-shuhn OH-vur uh-
DISH-uhn) Multiplying a sum by a number is the
same as multiplying each addend by that number
and then adding the two products.
a(bc) (a• b) (a• c). (p. 15)
Distributive Property of Multiplication over
Subtraction(diss-TRIB-yoo-tive PROP-ur-tee
UHV muhl-tuh-pluh-KAY-shuhn OH-vur suhb-
TRAK-shuhn) Multiplying the difference of two
numbers by a third number is the same as
multiplying each of the two numbers by the third
number and then subtracting the two products.
a(b c) (a• b) (a• c). (p. 15)
Division Property of Equality(di-VIZH-uhn
PROP-ur-tee UHV i-KWOL-uh-tee) When you
divide both sides of an equation by the same
nonzero number, the result is a true statement.
If a b, then , c 0. (p. 40)
Division Property of Inequality(di-VIZH-uhn
PROP-ur-tee UHV in-i-KWOL-uh-tee)
If ab and c is positive, then . If aband
c is negative, then . Similar statements can
be written for ab, a b, or a b. (p. 60)
domain (doh-MAYN) The set of input values, or
x-values, in ordered pairs. (p. 358)
E
edge (EJ) A line segment where two faces of a
polyhedron meet. (p. 302)
empty set (EMP-tee SET) When no number from
the replacement set makes the inequality true,
the solution set is the empty set, { } or. (p. 56)
enlargement (en-LARJ-muhnt) A dilation that is
greater than the original figure. (p. 374)
equally likely (EE-kwuhl-ee LIKE-lee) Events that
are just as likely to occur as other events. (p. 330)
equation(i-KWAY-zhuhn) A statement that
contains an equal sign, showing that two
mathematical expressions are equal. (p. 34)
equilateral triangle (ee-kwuh-LAT-ur-uhl
TRYE-ang-guhl) A triangle with three congruent
sides and angles. (p. 254)
equivalent fractions (i-KWIV-uh-luhnt
FRAK-shuhnz) Two fractions that have the same
value. (p. 111)
equivalent ratios(i-KWIV-uh-luhnt RAY-shee-ohz)
Two ratios that have the same value. (p. 148)
estimate (ESS-ti-mate) 1. To find an approximate
answer; to find an answer that is close to the
exact answer. (p. 78) 2. To determine if a fraction
is close to 1, close to , close to 0, close to ,
or close to 1 by comparing the absolute value of
its numerator to the absolute value of its
denominator. (p. 114)
evaluate(i-VAL-yoo-ate) To find the value of a
numerical expression or an algebraic expression.
(p. 32)
even odds (EE-vuhn ODZ) Odds that take the
form 1 : 1 in simplest form. (p. 339)
event (i-VENT) Any grouping of one or more
outcomes from the sample space. (p. 330)
exchange rate (eks-CHAYNJ RAYT) The
conversion factor in dimensional analysis. (p. 167)
experiment (ek-SPER-uh-ment) An event set up
to test a hypothesis. (p. 330)y
xa
cb
ca
cb
a c
cb
c1
21
2Glossary 427Extended Glossary