In math, a single apostrophe (tic mark) is used to mean "feet", "minutes", identify a variation on a variable or function name, or to indicate differentiation. If it is not pronounced "feet" or "minutes", it is usually pronounced "prime." That is, F' would be pronounced "eff prime."

Examples

30' may mean "30 feet" or "30 minutes" (of angle or of time, either one)

f, f', f'' may all be variants of some variable f that we want to discuss. (The latter might be pronounced "eff double-prime".)

F(x) may define some function, and F'(x) may be its derivative.

Examples

30' may mean "30 feet" or "30 minutes" (of angle or of time, either one)

f, f', f'' may all be variants of some variable f that we want to discuss. (The latter might be pronounced "eff double-prime".)

F(x) may define some function, and F'(x) may be its derivative.