Functions

Functions Evaluating Functions Graphing Functions

FunctionsEvaluating Functions

You can evaluate any function at any value using the key.

ExampleIf f(x) = 3x2 + 5x – 1, find f(–4)

ExampleIf f(x) = 3x2 + 5x – 1, find f(–4)

This means to evaluate the expression

3x2 + 5x – 1 when x has the value of –4

ExampleIf f(x) = 3x2 + 5x – 1, find f(–4)

This means to evaluate the expression

3x2 + 5x – 1 when x has the value of –4

Store –4 to x

ExampleIf f(x) = 3x2 + 5x – 1, find f(–4)

This means to evaluate the expression

3x2 + 5x – 1 when x has the value of –4

Store –4 to x

Enter the expression to be evaluated (exactly as shown)

ExampleIf f(x) = 3x2 + 5x – 1, find f(–4)

This means to evaluate the expression 3x2 + 5x – 1 when x has the value of –4

Store –4 to x

Enter the expression exactly as shown

Press

ExampleIf f(x) = 3x2 + 5x – 1, find f(-4)

The screen will look like:

Thus, f(-4) = 27

FunctionsGraphing 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=.

ExampleGraph the function f(x) = and label two

points on the graph.

32 x

ExampleGraph the function f(x) = and label two

points on the graph.

Consider y=

Enter the function as y=

(this gets absolute value)

32 x

32 x

ExampleGraph the function f(x) = and label two

points on the graph.

The screen will show:

The graph will look like this:

32 x

ExampleTo find two points on the graph, pressto find one and move the arrow key to findanother 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 2nd GRAPHsee a table of values.

ExampleGraph the function f(x) = -2x2 – 4x + 1

and label two points on the graph.

ExampleGraph the function f(x) = -2x2 – 4x + 1

and label two points on the graph.

Consider y = -2x2 – 4x + 1

Enter the function as y=

The window will show:

ExampleGraph the function f(x) = -2x2 – 4x + 1

and label two points on the graph.

The screen will show:

The graph will look like this:

ExampleTo find two points on the graph, pressto find one and move the arrow key to findanother 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 2nd GRAPHsee a table of values.