e is used in diverse areas, such as in the formula for the catenary shape of a hanging rope supported at its two ends, in the calculation of compound interest, and in numerous applications in probability and statistics.
It also appears in one of the most amazing mathematical relationships ever discovered, -e- +1=0, which unites the five most important symbols of mathematics: 1,0, ,e, and i (the square root of minus one).
Harvard mathematician Benjamin Pierce said that "we cannot understand [the formula], and we don't know what it meanes, but we have proved it, and therefore we know it must be the truth."
Several surveys among mathematicians have placed this formula at the top of the list for the most beautiful formula in mathematics.
Euler's Number, e
Kasner and Newman note, "We can only reproduce the equation and not stop to inquire into its implications.
It appeals equally to the mystic, the scientist, and the mathematician."