Using only math symbols (no functions like sin, cos, log, etc.) create an expression with only two 2s equal to 5 (no other digits or constants).

It says "no functions like sin, cos, log, etc." It doesn't say "no functions, like sin, cos, log, etc."  The absence of a comma makes the "like..." phrase restrictive.  The only question is What makes a given function "like" one of those functions. ... that it be a function of one argument, or that it is a function that requires letters to spell it out?

Coming parenthetically after "only math symbols", I'd think it refers to functions that require letters rather than symbols, as a reinforcing repetition of the "only math symbols" requirement. So sqrt (when symbolized), !, [ ... ] (floor) should be legitimate math-symbol type functions, and we don't even have to worry as to whether + is a function, since it's represented by a symbol rather than letters.

Posted by Charlie on 2005-10-15 15:21:50