Page 38 - Appplied Mathematics for the Petroleum and Other Industries, 5th Edition

298 GLOSSARY

common denominator n: a shared denominator in a the sun, rather than the time it takes the Earth to make
series of fractions to be added or subtracted. one axial rotation.
cosecant (cs) n: in a right triangle, the ratio of the hy- equals key n: the key on a computer or calculator that
potenuse to the side opposite a given angle, also known allows the user to enter an equal sign into the display.
as the reciprocal of the sine function. See sine. equation n: in mathematics, a statement that each of
cosine (cos) n: in a right triangle, the ratio of the side two expressions is the same as (is equal to) the other. For
adjacent to a given angle to the hypotenuse. example, a = b is an equation, as is 2 + 5 = 3 + 4.
cotangent (cot) n: in a right triangle, the ratio of the exponent n: in mathematics, a number or symbol, such
side next to a given angle to the side opposite the given as the 3 in x , placed to the right of and above another
3
angle, also known as the reciprocal of the tangent func- number, symbol, or expression, denoting the power to
tion. See tangent. which that number, symbol, or expression is raised to.
current n: the flow of electric charge or the rate of such Also called power.
flow, measured in amperes.
extremes n: the first and fourth terms of a proportion.
current output n: the range of electrical current, mea-
sured in milliamperes (mA), which the electronic instru-
ment produces during operation. foot n: a unit of distance equal to 12 inches or 30.48 cm.
formula n: a symbolic expression of a general math-
ematical or scientific fact, rule, or principle, often stated
decimal key n: the key on a computer or calculator that as an equation.
allows the user to enter a decimal point into the display.
See decimal point. fundamental quantity n: a quantity that cannot normally
be divided into other quantities. The seven fundamental
decimal point n: a period (.) placed to the left of the first quantities are length, mass, time, electricity, luminous
digit in the decimal fraction. intensity, temperature, and amount of a substance.
decimal system n: the standard base ten number system.
denominator n: in a mathematical fraction, the term or gauge pressure (psig) n: 1. the amount of pressure exert-
number that divides the other term or number (called ed on the interior walls of a vessel by the fluid contained
the numerator) and is written below the line.
in it (as indicated by a pressure gauge). It is expressed in
density n: the mass or weight of a substance per unit pounds per square inch gauge or in kilopascals. Gauge
volume. pressure plus atmospheric pressure equals absolute
derived quantity n: a non-fundamental quantity that pressure. 2. pressure measured relative to atmospheric
scientists derived from the seven fundamental quantities. pressure considered as zero.
See fundamental quantity. graph n: a diagram that indicates relationships between
difference n: See remainder. two or more variables.
dimension n: another term for a fundamental quantity.
See fundamental quantity. hypotenuse n: the side of a right triangle that is the
dividend n: the number to be divided in a division longest and located opposite the right angle.
problem.
divisor n: the number that does the dividing in a divi- ideal gas law n: the equation of the state of an ideal gas,
sion problem. showing a close approximation to real gases at sufficiently
high temperature and low pressures. Combining Boyle’s
Petroleum Extension-The University of Texas at Austin
law with Charles’ law, it states that the volume of a
electromotive force (emf) n: 1. the force that drives
electrons and thus produces an electric current. 2. the quantity of gas varies inversely as the absolute pressure
voltage or electric pressure that causes an electric current and directly as the absolute temperature.
to flow along a conductor. 3. a difference of potential, improper fraction n: a fraction in which the numerator
or electrical, flow through a circuit against a resistance. is larger than the denominator.
ephemeris second n: an astronomical term based on the inch n: a unit of distance equal to one-twelfth of a foot
amount of time it takes for the Earth to orbit around or 2.54 cm.