A question on pi...

Pi is the ratio of the circumference to the diameter of every circle. You can calculate it with any of several results obtainable through calculus of a type called a Taylor series expansions.

Just as so-called common logarithms have base 10, natural logarithms have the number e as their base. e is about 2.718. I do not know how to define natural logarithms without referring to calculus.

Pi is the ratio of the circumference to the diameter of a circle.

See Pi

e is a natural number that is equal to area bounded by the hyperbola y=1/x the x axis and the vertical limits x=1 and x=e. Consequently e is is real handy as a logarithm base (natural vs common-base 10 logrithms).

See e

BTW click on the blue Pi & e to connect to websites on Pi & e that will probably tell you more than you want to know.

Rap

Other thoughts
On PI, everyone knows the 22/7 approximatation. A much better one is 355/113.

On e, e is also the limit of (1 + 1/n) ^ n as n goes to infinity. If you expand that out, you can see it is also the limit of the summation of the series 1/n! where n goes from 0 to infinity.

allright, thanks a lot