# Algebra II : Functions as Graphs

## Example Questions

### Example Question #1 : Introduction To Functions

Which analysis can be performed to determine if an equation is a function?

Vertical line test

Calculating zeroes

Horizontal line test

Calculating domain and range

Vertical line test

Explanation:

The vertical line test can be used to determine if an equation is a function. In order to be a function, there must only be one  (or ) value for each value of . The vertical line test determines how many  (or ) values are present for each value of . If a single vertical line passes through the graph of an equation more than once, it is not a function. If it passes through exactly once or not at all, then the equation is a function.

The horizontal line test can be used to determine if a function is one-to-one, that is, if only one  value exists for each  (or ) value. Calculating zeroes, domain, and range can be useful for graphing an equation, but they do not tell if it is a function.

Example of a function:

Example of an equation that is not a function:

### Example Question #2 : Introduction To Functions

Which graph depicts a function?

Explanation:

A function may only have one y-value for each x-value.

The vertical line test can be used to identify the function. If at any point on the graph, a straight vertical line intersects the curve at more than one point, the curve is not a function.

### Example Question #281 : Algebra

The graph below is the graph of a piece-wise function in some interval.  Identify, in interval notation, the decreasing interval.

Explanation:

As is clear from the graph, in the interval between  ( included) to , the  is constant at  and then from ( not included) to  ( not included), the  is a decreasing function.

### Example Question #1 : Functions And Graphs

Without graphing, determine the relationship between the following two lines. Select the most appropriate answer.

Supplementary

Perpendicular

Intersecting

Complementary

Parallel

Perpendicular

Explanation:

Perpendicular lines have slopes that are negative reciprocals.  This is the case with these two lines.  Although these lines interesect, this is not the most appropriate answer since it does not account for the fact that they are perpendicular.

### Example Question #4 : Introduction To Functions

Find the slope from the following equation.

Explanation:

To find the slope of an equation first get the equation in slope intercept form.

where,

represents the slope.

Thus

### Example Question #1 : Functions As Graphs

3 spaces right, 2 spaces down

3 spaces up, 2 spaces left

3 spaces right, 2 spaces up

3 spaces left, 2 spaces down

3 spaces left, 2 spaces down

Explanation:

When determining how a the graph of a function will be translated, we know that anything that happens to x in the function will impact the graph horizontally, opposite of what is expressed in the function, whereas anything that is outside the function will impact the graph vertically the same as it is in the function notation.

For this graph:

The graph will move 3 spaces left, because that is the opposite sign of the what is connected to x directly.

Also, the graph will move down 2 spaces, because that is what is outside the function and the 2 is negative.

### Example Question #3 : Introduction To Functions

Define a function .

Is this function even, odd, or neither?

Odd

Even

Neither

Odd

Explanation:

To identify a function  as even odd, or neither, determine  by replacing  with , then simplifying. If , the function is even; if  is odd.

,

so

By the Power of a Product Property,

,

so  is an odd function

### Example Question #7 : Introduction To Functions

Define a function .

Is this function even, odd, or neither?

Neither

Even

Odd

Neither

Explanation:

To identify a function  as even odd, or neither, determine  by replacing  with , then simplifying. If , the function is even; if  is odd.

so

By the Power of a Product Property,

, so  is not an even function.

,

, so  is not an odd function.

### Example Question #8 : Introduction To Functions

Define a function .

Is this function even, odd, or neither?

Even

Odd

Neither

Even

Explanation:

To identify a function  as even, odd, or neither, determine  by replacing  with , then simplifying. If , the function is even; if  is odd.

, so  is an even function.

### Example Question #1 : Introduction To Functions

Define a function .

Is this function even, odd, or neither?

Odd

Even

Neither