decagonA 10-sided POLYGON.
decibel AUNITthat expresses the intensity of sound as a FRACTIONof the
intensity of a BEL. One decibel is equal to –– 101 of a bel. The symbol for
decibel is dB.
decimal The decimal system is a number system based on 10s. Usually,
decimals refer to decimal fractions,so 3–– 101 is written as 3.1, 76 100 —^95 is
written as 76.95, and so on.
decimal fractionAny FRACTIONwith a DENOMINATORthat is a power of 10,
such as –– 101 , 100 —^37 ,—– 1000629 , and so on. This kind of fraction is usually
written in DECIMALform, for example, –– 101 is written as .1, 100 —^37 is
written as .37, and —– 1000629 is written as .629.
decimal pointA dot used in base 10 number systems to show both INTEGER
and FRACTIONvalues. The numbers to the left of the dot are the
integers, and the numbers to the right of the dot are the fractions. For
example, 0.4, 3.6, 1.85, 97.029, and so on.
deficient number (defective number)Any number whose FACTORS
(excluding the number itself), when added up, equal less than the
number itself. For the number 14, the factors are 1, 2, and 7. When
these numbers are added, the SUMis 10, making 14 a deficient
number.
degree of a polynomialThe degree of the highest EXPONENTin a POLYNOMIAL.
For example, in the polynomial 21 – x+ 5xy^2 +π,the degree is 2
because the highest exponent of 2 is found in the TERM 5 xy^2.
See alsoSECTION IV CHARTS AND TABLES.
denominatorThe number in a FRACTIONthat is below the division line,
showing how many equal parts the WHOLE NUMBERhas been divided
into. For example, in^1 – 2 , the denominator is 2, meaning that the whole
has been divided into 2 equal parts. In–^34 the denominator is 4, and the
whole has been divided into four equal parts. In–^78 the denominator is
8, in— 169 the denominator is 16, and in— 10097 the denominator is 100.
ZEROis never used as a denominator.
See alsoSECTION IV CHARTS AND TABLES.
dependent variableThe VARIABLEthat relies on another variable for its
VALUE. For example, in A=πr^2 , the value of the AREAdepends on
the value of the RADIUS, so Ais the dependent variable.
description method of specification (rule method)The method in
which the elements, or MEMBERS, of a SETare described. For
example, A= {the EVEN NUMBERs between 0 and 10}. An
decagon – description method of specification GLOSSARY
decagon – description method of specification GLOSSARY