1. Functions

2. Evaluating Functions Graphing Functions

3. Functions Evaluating Functions You can evaluate any function at any value using the key.

4. Example If f(x) = 3x 2 + 5x – 1, find f(–4)

5. Example If f(x) = 3x 2 + 5x – 1, find f(–4) This means to evaluate the expression 3x 2 + 5x – 1 when x has the value of –4

6. Example If f(x) = 3x 2 + 5x – 1, find f(–4) This means to evaluate the expression 3x 2 + 5x – 1 when x has the value of –4 Store –4 to x

7. Example If f(x) = 3x 2 + 5x – 1, find f(–4) This means to evaluate the expression 3x 2 + 5x – 1 when x has the value of –4 Store –4 to x Enter the expression to be evaluated (exactly as shown)

8. Example If f(x) = 3x 2 + 5x – 1, find f(–4) This means to evaluate the expression 3x 2 + 5x – 1 when x has the value of –4 Store –4 to x Enter the expression exactly as shown Press

9. Example If f(x) = 3x 2 + 5x – 1, find f(-4) The screen will look like: Thus, f(-4) = 27

10. Functions Graphing Functions You can graph any function of the form f(x) = by letting y = f(x). Just remember y= and f(x)= mean the same thing. That is, when you are given a function f(x), enter that in your calculator as Y=.

11. Example Graph the function f(x) =and label two points on the graph.

12. Example Graph the function f(x) =and label two points on the graph. Consider y= Enter the function as y= ( this gets absolute value)

13. Example Graph the function f(x) =and label two points on the graph. The screen will show: The graph will look like this:

14. Example To find two points on the graph, press to find one and move the arrow key to find another one (or look at the table) The window will show: This gives you one ordered pair (0,3), move cursor to find another one or press 2 nd GRAPH see a table of values.

15. Example Graph the function f(x) = -2x 2 – 4x + 1 and label two points on the graph.

16. Example Graph the function f(x) = -2x 2 – 4x + 1 and label two points on the graph. Consider y = -2x 2 – 4x + 1 Enter the function as y= The window will show:

17. Example Graph the function f(x) = -2x 2 – 4x + 1 and label two points on the graph. The screen will show: The graph will look like this:

18. Example To find two points on the graph, press to find one and move the arrow key to find another one (or look at the table). The window will show: This gives you one ordered pair (0,1), move cursor to find another one or press 2 nd GRAPH see a table of values.