e -- from Wolfram MathWorld

The constant is base of the natural logarithm. is sometimes known as Napier's constant, although its symbol () honors Euler. is the unique number with the property that the area of the region bounded by the hyperbola , the x-axis, and the vertical lines and is 1. In other words, With the possible exception of , is the most important constant in mathematics since it appears in myriad mathematical c