Well math is a sport but that's not what I meant to ask. What's your favorite equation then?
My favorite equation isn't quite complicated but the beauty in the pattern never ceases to astound me:
(1+2+3+...+n)^2 = (1^3+2^3+3^3+...+n^3)
Another favorite is the formula to calculate the sum of a finite arithmetic series:
Where n is the number of terms, a(1) is the first term of the series, and a(n) is the last term of the series.
The formula itself amazes me less than the story I read in my textbook in which this formula was used by a young math student, Carl Friedrich Gauss, when his teacher punished him by putting him in a corner and telling him to add all of the integers from 1 to 100. In a matter of seconds (and without a developed formula at the time), Gauss responded with 5050. The teacher was dumbfounded, and probably had to add the integers up to 100 just to check his work.