2.7182818... what is this?

Question

What is it?What kind of number is it exactly? And what kind of context is it used it or can it be found in?

Thank you :]

Answer 1

It's the constant e in math:

http://en.wikipedia.org/wiki/E_(mathemat...

Answer 2

to the nearest  8 of a significant figure or 7 decimal point.maybe a recurring decimal.(but doesn't look like one.)

Answer 3

That looks like the start of the exponential constant, "e".  Like π (pi), it's a special irrational number used in mathematics.

>>And what kind of context is it used it or can it be found in?

Originally, e was discovered to deal with a banking problem: how do you compute interest that's compounded not quarterly, not daily, but CONTINUOUSLY?  The constant "e" shows up in the results.

The number strangely shows up in a number of other problems: statistics (so many statistics show up as the bell curve, whose shape you can describe in terms of e), radioactive decay, population growth, etc.

e is defined as the limit of (1 + 1/n)^n.  In other words, if you plug in higher and higher numbers for n into that expression, you get a result that's closer and closer to e.  It's also the sum of (1/1) + (1 / 1*2) + (1 / 1*2*3) + (1 / 1*2*3*4) + ... and so on to infinity.

These pages give more descriptions:

http://mathforum.org/dr.math/faq/faq.e.h...

http://mathforum.org/library/drmath/view...

Answer 4

It's called e.  It's one of those classic numbers, like pi.  It's all bound up in things like the Golden Ratio and in used in the calculation of continuously compounding interest.

Interestingly enough, e ^ (-i * pi) = -1

Answer 5

that the exponential raised to the power of 1

or

just   "  e   "  

Answer 6

e=lim as n approaches infinity of [1+(1/n)]^n

e = 2.71828182.... an irrational number

The natural log ln is also based on e.

Remember ln e = 1

e is very important in the study of Calculus.

d(ln x) = (1/x) dx for x>0

etc