Hanz™ posted on Jul 16 2005 at 12:37 PM said:
Jarska333 posted on Jul 16 2005 at 09:35 AM said:
Well at in maths it means "unknown".
Well every letter in maths (well most anyway) mean unknown.
From my Mathematical Dictionary,
a- Prefix meaning 'not'.
A The number 10 in hexadecimal notation.
B The number 11 in hexadecimal notation.
c Abbreviation for centi.
C The set of complex numbers.
C The Roman numeral for 100.
C The number 12 in hexadecimal notation.
d The symbol used to denote the differential operator.
D The Roman numeral for 500.
D The number 13 in hexadecimal notation.
e The number which is the base of natural logarithms (2.71828183 to 8 decimal places.)
e (in conics) The symbol for eccentricity of a conic.
e (in group theory) A common notation for the neutral element in a group.
E The number 14 in hexadecimal notation.
f Symbol for a function.
F The number 15 in hexadecimal notation.
g Constant, which is the magnitude of the acceleration due to gravity (9.81 to 2 decimal places.)
i An imaginary number, where i²=-1.
i (or
i) a unit vector, usually in the direction of the x-axis.
I The Roman numeral for 1.
j Used by some engineers instead of the imaginary number i.
j (or
j) a unit vector, usually in the direction of the y-axis.
J Symbol for Joule.
k Abbreviation for kilo.
k (or
k) a unit vector, usually in the direction of the z-axis.
m Abbreviation and symbol for metre.
m Abbreviation for milli.
M The Roman numeral for 1000.
n Abbreviation for nano.
n- Prefix when denoting a finite but unspecified number in a description.
N Symbol for Newton.
p Abbreviation for pico.
Q The set of rational numbers.
R The set of real numbers.
T Symbol for a transpose of a matrix.
T Symbol for 'true' in logic and truth tables.
V The Roman numeral for 5.
W Symbol for Watt.
X The Roman numeral for 10.
x-axis One of the axes in a Cartesian co-ordinate system.
y-axis One of the axes in a Cartesian co-ordinate system.
Z The set of integers.
z-axis One of the axes in a Cartesian co-ordinate system.
Out of those I would use a,b,c,d or e for unknown constants, and x,y and z for unknown variables (as they can be plotted on graphs). There were four letters not in the dictionary h, o, s and u, but I have certainly used all of them in my Maths, and Physics lessons.
h Plank constant (6.63x10^-34 to 3 significant figures)
O The origin in a Cartesian co-ordinate system.
u Initial velocity in 'UVAST' equations.
s Displacement in 'UVAST' equations.
(This isn't really a dig at anyone, it's just me)
