the part of mathematics in which letters and other general symbols are used to represent numbers and quantities in formulae and equations. a system of algebra based on given axioms.
Some numbers, such as your phone number or your Social Security number, are decidedly more important than others. One of the cornerstones of Algebra, frankly all of mathematics, is numbers! Here is my list of some of the most important numbers in Algebra:
1) Of course the first number must be: 1!!
The number one is far more special than a prime! It is the unit (the building block) of the positive integers, hence the only integer which merits its own existence axiom in Peano’s axioms. It is the only multiplicative identity (1.a = a.1 = a for all numbers a). It is the only perfect nth power for all positive integers n. It is the only positive integer with exactly one positive divisor. But it is not a prime.
source: Primes FAQ
2) Archimedes’ Constant (Pi): 3.1415…
Archimedes’ constant, or “Pi,” is the name given to the ratio of the circumference of a circle to the diameter, but it’s actually so much more than that.
Greek mathematician Archimedes is credited with the first theoretical calculation of Pi, which he estimated was between 3 10/71 and 3 1/7 — or 223/71.
Pi is now defined as 3.1415926535… etc
Application: Pi is the key constant in any equation that involves circular or harmonic motion. It’s one of the most essential relationships in mathematics.
Imaginary Unit: i
“i” equals the square root of -1, which means that i squared is equal to -1.
Application: Negative numbers don’t have square roots. Math had advanced to the point where saying “there is no square root of negative numbers” was holding back a lot of progress.
Solutions of some polynomials have both real solutions that we could use in real life as well as solutions that involved the square root of a negative number, which can be discarded.