Chapter 1 Functions
Domain = [0, ∞) Range = *0, ∞)
Conclusion and Definition • Not every relation is a function. • Every function is a relation. • Definition: Let X and Y be two nonempty sets. A function from X into Y is a relation that associates with each element of X exactly one element of Y.
Types of functions (*7*) • • • • • • •
Algebraic Functions (4) Exponential Functions (3) Logarithmic Functions (3) Trigonometric Functions (6) inverse trigonometric Functions (6) hyperbolic Functions (6) Inverse Hyperbolic Functions (6)
Note that • In discrete math, we frequently use the following functions over real numbers: x (“floor of x”) is the largest integer x. x (“ceiling of x”) is the smallest integer x.
• Real numbers “fall to their floor” or “rise to their ceiling.” • Note that if xZ, x x & x x • Note that if xZ, x = x = x.