DEFINITION A function is a rule or correspondence which associates to each number x in a set A a unique number f(x) in a set B.
The set A is called the domain of f and the set of all f(x)'s is called the range of f. |
FUNCTIONSy = f (x) single-valued function
∕ { ( 2 , 3 ) , ( 3 , 4 ) , ( 5 , 2 ) } X (not a function) { ( 6 , -1 ) , ( 6 , -2 ) , ( 3 , -2 ) } ∕ { ( 1 , 1 ) , ( 2 , 1 ) , ( 3 , 1 ) } |