Is
it irrational to celebrate a number today?
Like
“Pi Day” (March 14), “e Day” celebrates one of the most
famous and useful irrational numbers. “Irrational” means “not
rational,” and in math it refers to numbers that cannot be
expressed as simple fractions, or ratios.
The
irrational number e
starts
out 2.7182818284590452353602874713527...but
it goes on and on without stopping or repeating a pattern. Because
the first two numbers are 2 and 7, we celebrate e
on 2/7, or February 7.
I
bet you're wondering how on earth such a cumbersome number can be
famous and useful! Well, this number is the base of the natural
logarithms, and it is also used in compounding interest, which is how
your bank account or other investment can increase. More money =
useful!
The
constant e
also
shows up in such places as graphs of growth or decay, the statistical
bell curve, and the shape of a hanging cable or a standing arch.
(By
the way, the logarithm of a number is the exponent by which the base
must be raised to produce that number. Logarithms are useful in
science, engineering, calculus, and computer science.)
For
more about this irrational number, check out Math Is Fun.
Also
on this date:
No comments:
Post a Comment