back to Unit 19

 

Function: An equation with two variables (lets call them x and y).  Where for every value of x there is only one value of y.

*Domain: The set of all possible values for x.

*Range: The set of all values of y

Example: y = 2x +1  where the domain is {-2, -1, 0, 1, 2}

To solve plug in all the values of x into the equation using a t- chart

.                                                                               

y = 2x + 1

x y
-2 2 ● -2 + 1 = -3
-1 2 ● -1 + 1 = -1
0 2 ● 0 + 1 = 1
1 2 ● 1 + 1 = 3
2 2 ● 2 + 1 = 5



Example of a  Common Function:
             Distance = Rate Time or  (where d = distance; r = rate and t = time)
                             d = rt

Make a table of input and output for the above function when There is a constant rate of
r = 2 miles per minute  and
t = 5 minutes, 10 minutes, 15 minutes, 20 minutes and 25 minutes

 

 

           Function:            d = 2t

Input (time) (t) Output (distance) (d)
5 10
10 20
15 30
20 40
25 50