Relations and Functions

Relations and Functions

1. RELATION

   • A set of coordinates, it relates an x with a y
     • (3,2) (5,2)

2. FUNCTIONS

   • A relation in which the x values are unique. One x corresponds with one y
     • (1,2)(2,4)
   • Dependency
     • In a function, the value of an x determines the value of the y
       • Ex: The height of a child depends on its age.

3. Domain

   • All the x values of a function
     • Ex: (-∞,∞)
     • Sometimes the graphs are discontinuous, so both intervals are put together with a u, which represents a union.
       • Ex: (-∞,3) u (5,∞)

4. Range

   • All the y values of a function
     • Ex: (-∞,∞)
     • When a graph is discontinuous, both intervals are put together with a u
       • Ex: (-∞,6) u (6,∞)