Evaluating Functions

Evaluating Functions

f(x) notation can be thought of as another way representing the y-value in a function.

f(x) notation can be thought of as another way representing the y-value in a function.

The following are but a few of the notations that may be used to name a function:

The following are but a few of the notations that may be used to name a function:

Example 1:

Example 1:

When evaluating functions,

When evaluating functions,

You used to say: y = 2x + 3 Evaluate if x = -1 Now you say: f (x) = 2x + 3 find f(-1) Try: Consider the function f (x) = 2x - 5. Find f (5).

You used to say: y = 2x + 3 Evaluate if x = -1 Now you say: f (x) = 2x + 3 find f(-1) Try: Consider the function f (x) = 2x - 5. Find f (5).

Use the graph to find the values indicated:

Use the graph to find the values indicated:

f (5) = ___

f (5) = ___

Example 2:

Example 2:

When evaluating functions,

When evaluating functions,

You used to say: y = 2x + 3 Solve for x if y = 17 Now you say: f (x) = 2x + 3 If f (x)= 17, x = ___ Try: f (x) = 2x - 5 If f (x) = 1, then x = ___

You used to say: y = 2x + 3 Solve for x if y = 17 Now you say: f (x) = 2x + 3 If f (x)= 17, x = ___ Try: f (x) = 2x - 5 If f (x) = 1, then x = ___

Use the graph to find the values indicated:

Use the graph to find the values indicated:

f (x) = 1, x = ___

f (x) = 1, x = ___