College Algebra : College Algebra

Study concepts, example questions & explanations for College Algebra

varsity tutors app store varsity tutors android store

Example Questions

Example Question #6 : Transformations

Consider an exponential function . If we want to reflect this function across the y-axis, which of the following equations would result in the desired reflection?

Possible Answers:

Correct answer:

Explanation:

As a general rule, if you have a function , then in order to reflect across the x-axis, we compute , and in order to reflect across the y-axis, we compute . In our case, we are asked to compute the latter.

So, if , then .

Example Question #5 : Transformations

If we want a function  to be reflected about the origin, what would the corresponding equation look like?

Possible Answers:

Correct answer:

Explanation:

To compute a reflection about the x-axis, calculate , and to calculate a reflection about the y-axis, calculate . To compute a reflection about the origin, simply combine both reflections into .

In our case, .

So, 

Example Question #5 : Transformations

Give the equation of the horizontal asymptote of the graph of the equation 

.

Possible Answers:

The graph of  does not have a horizontal asymptote.

Correct answer:

The graph of  does not have a horizontal asymptote.

Explanation:

Let . In terms of ,

, being a logarithmic function, has a graph without a horizontal asymptote. As  represents the result of transformations of , it follows that its graph does not have a horizontal asymptote, either.

Example Question #61 : Graphs

Give the equation of the vertical asymptote of the graph of the equation 

.

Possible Answers:

Correct answer:

Explanation:

Let . In terms of ,

The graph of  has as its vertical asymptote the line of the equation . The graph of  is the result of three transformations on the graph of - a right shift of 3 units (  ), a vertical stretch (  ), and a downward shift of 2 units (  ). Of the three transformations, only the right shift affects the position of the vertical asymptote; the asymptote of  also shifts right 3 units, to .

Example Question #61 : Graphs

Define 

and

.

Which two transformations must be performed in the graph of  in order to obtain the graph of ?

Possible Answers:

The graph of  must be translated two units left, then reflected about the -axis.

The graph of  must be translated two units left, then reflected about the -axis.

None of the other choices gives the correct response.

The graph of  must be translated two units right, then reflected about the -axis.

The graph of  must be translated two units right, then reflected about the -axis.

Correct answer:

The graph of  must be translated two units right, then reflected about the -axis.

Explanation:

, so the graph of  is the result of performing the following transformations:

1)  is the result of translating this graph two units right.

2)  is the result of reflecting the new graph about the -axis.

Example Question #62 : Graphs

The graph of a function  is reflected about the -axis, then translated upward  units. Which of the following is represented by the resulting graph?

Possible Answers:

Correct answer:

Explanation:

Reflecting the graph of a function  about the -axis results in the graph of the function

.

Translating this graph upward  results in the graph of the function

.

Example Question #63 : Graphs

Translate the graph of  upward three units to yield the graph of a function . Which of the following is a valid way of stating the definition of ?

Possible Answers:

Correct answer:

Explanation:

A vertical translation of the graph of a function  by  units yields the graph of the function . A translation in an upward direction is a positive translation, so setting  and , the resulting graph becomes

or

Apply properties of logarithms to rewrite this as

.

Example Question #64 : Graphs

Reflect the graph of  about the -axis to yield the graph of a function . Which of the following is a valid way of stating the definition of ?

Possible Answers:

None of the other choices gives the correct response.

Correct answer:

Explanation:

The reflection of the graph of a function  about the -axis yields the graph of the function . Therefore, set  and substitute  for  to yield the function

.

Example Question #1 : Symmetry

Determine the symmetry of the following equation.

 

Possible Answers:

Symmetry along the x-axis.

Symmetry along all axes. 

Does not have symmetry.

Symmetry along the y-axis.

Symmetry along the origin.

Correct answer:

Does not have symmetry.

Explanation:

To check for symmetry, we are going to do three tests, which involve substitution. First one will be to check symmetry along the x-axis, replace .

This isn't equivilant to the first equation, so it's not symmetric along the x-axis.

Next is to substitute .

This is not the same, so it is not symmetric along the y-axis.

For the last test we will substitute , and 

This isn't the same as the orginal equation, so it is not symmetric along the origin.

The answer is it is not symmetric along any axis.

Example Question #2 : Symmetry

Untitled

Which of the following is true of the relation graphed above?

Possible Answers:

It is a function, but it is neither even nor odd.

It is an even function

It is an odd function

It is not a function

Correct answer:

It is an odd function

Explanation:

The relation graphed is a function, as it passes the vertical line test - no vertical line can pass through it more than once, as is demonstrated below:

Untitled

Also, it can be seen to be symmetrical about the origin. Consequently, for each  in the domain,  - the function is odd.

Learning Tools by Varsity Tutors