|A, B are two sets. f is a relation from A into B. If f is such that for every a Î A and there is a unique b Î B such that (a,b) Î f, then f is said to be a function from A into B.
If f is a function from A into B then we write it f:A ® B and we read this as f maps A into B.
A function is also called a mapping.
A is called the domain of f and B is called the co-domain of f. The set of f(A) of all images of elements of A under the mapping f is called the range of f.
Directions: Choose the correct answer. Write at least ten examples of relations and if they are functions or not functions. Also draw graph of increasing, decreasing, constant functions, even and odd functions, identity function, square root function, cube root function and absolute value function.