Module 4 Topic 1Coordinate Planes/Midpoint/Relations and Functions

Example 1

Similar Problem: Follow these directions on a blank coordinate plane: Begin at the origin, move right 5 units, down 4 units. What are the coordinates of the ordered pair have you just graphed?

Right 5 is going to be x = 5

Down 4 is going to be y = -4

(5, -4)

Example 2

For a function to exist, if you are looking at a set of ordered, none of the x-values can repeat. So if the x-values repeat at all then it is not a function.

Example 3

For a function to exist, if you are looking at a table, none of the x-values can repeat. So if the x-values repeat at all then it is not a function.

Example 4

Remember that if you have a vertical line it is not a function because it does not pass the vertical line test.

Example 5

Similar Problem: Let f(x) = 10x - 5.5. Find the value of f(3).

10x - 5.5 Plug in 3 for x and evaluate.

10(3) - 5.5

30 - 5.5

24.5

Example 6

Similar Problem: Let g(x) = x2 - 4x + 9. Find the value of g(-3)

Plug in -3 for x.

x2 - 4x + 9

(-3)2 - 4(-3) + 9

9 - (-12) + 9

9 + 12 + 9

30