Using only standard math operators (+, -, *, /) and functions (absolute value, square root, powers, and so on), give a function that calculates MAX(A,B,C).
Alternate version, for programmers only: using any language (BASIC, C, Excel, whatever) find the maximum of A, B, and C, but be careful when writing the program, because you cannot use the ">" key, for it's broken (thus writing things like IF A>B is impossible...) and you cannot use the "M" key either, for it's also broken (...and writing H=MAX(A,B) is also not possible.)
For two variables you can use this:
MAX(A,B) = (A+B+|A-B|)/2
Intuitively, (A+B)/2 is the value half way between A and B. Adding |A-B|/2 results in the larger of A and B.
For three arguments, use:
MAX(A,B,C) = MAX(A,MAX(B,C))
After some simplification you'd get