The Facts On File Algebra Handbook

ellipses A series of three dots, ... , used to indicate that a series of numbers
continues on in the same pattern. For example, {2, 4, 6, 8,.. .}
indicates that the SETcontinues on with EVEN NUMBERs; {10, 20,
30, 40,.. .} indicates that the set continues on by tens.

empirical probabilityThe PROBABILITYof a future event happening, given
the actual data of the event happening in the past.

empty set (null set)ASETthat contains no elements. For example, if A=
{the ODD NUMBERs in the group 2, 4}, then Ahas no elements in it,
and is considered an empty set. An empty set is designated with the
symbol ∅.Since an empty set has no elements in it, the empty set is
considered a SUBSETof every set.

equality (equals)Exactly the same VALUEin quantity between two
EXPRESSIONs, usually shown with the symbol =.

equationAny MATHEMATICAL SENTENCEthat contains an “equals” (=)
symbol. For example, 3nis an EXPRESSION, 3 +n< 12 is a
mathematical sentence, and 3 + n= 12 is an equation because it
contains the = symbol.

equidistantThe exact same DISTANCEapart at every point of reference, as in
PARALLEL LINES.

equilateral triangleATRIANGLEin which all three sides are equal in length.
See alsoSECTION IV CHARTS AND TABLES.

equivalent equationsEQUATIONs that have the same SOLUTIONor
solutions.

Euler’s f(x) notationThe notation to indicate a FUNCTION, using “f” as the
symbol for function, and (x)as the VARIABLEof the function.

evaluating expressionsDetermining the VALUEof an EXPRESSIONby
substituting the appropriate numbers for the VARIABLEs and then
calculating the EQUATION.

even numberAny number that is exactly divisible by 2. Numbers that end in
0, 2, 4, 6, or 8 are even numbers.
See alsoSECTION IV CHARTS AND TABLES.

evolutionThe reverse of INVOLUTION; the process of finding the root of a
quantity.

exponentNumbers or symbols used to identify the POWERto which an
EXPRESSIONis to be multiplied. For example, 5^2 is read “five to the
second power” or “five squared” and means 5 ×5. “Five to the third

ellipses – exponent GLOSSARY

ellipses – exponent GLOSSARY

Empty set

Equilateral triangle