Algebra II : Algebra II

Study concepts, example questions & explanations for Algebra II

varsity tutors app store varsity tutors android store

Example Questions

Example Question #15 : Transformations

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

Possible Answers:

The graph of  has no horizontal asymptote.

Correct answer:

Explanation:

Define  in terms of 

It can be restated as the following:

The graph of  has as its horizontal asymptote the line of the equation . The graph of  is a transformation of that of  —a right shift of 2 units  , a vertical stretch   , and an upward shift of 5 units  . The right shift and the vertical stretch do not affect the position of the horizontal asymptote, but the upward shift moves the asymptote to the line of the equation . This is the correct response.

Example Question #11 : Transformations

Shift  down three units.  What is the new equation?

Possible Answers:

 

Correct answer:

 

Explanation:

The equation is currently in standard form.  Rewrite the current equation in slope-intercept form.  Subtract  from both sides.

Since the graph is shifted downward three units, all we need to change is decrease the y-intercept by three.  Subtract the right side by three.

The answer is:  

Example Question #1 : Inverse Functions

Which of the following represents ?

Possible Answers:

Correct answer:

Explanation:

The question is asking for the inverse function. To find the inverse, first switch input and output -- which is usually easiest if you use notation instead of . Then, solve for .

Here's where we switch:

To solve for , we first have to get it out of the denominator. We do that by multiplying both sides by .

Distribute:

Get all the terms on the same side of the equation:

Factor out a :

Divide by :

This is our inverse function!

Example Question #2 : Inverse Functions

What is the inverse of the following function?

Possible Answers:

Correct answer:

Explanation:

Let's say that the function  takes the input  and yields the output . In math terms:

So, the inverse function needs to take the input  and yield the output :

So, to answer this question, we need to flip the inputs and outputs for . We do this by replacing  with  (or a dummy variable; I used ) and  with . Then we solve for  to get our inverse function:

Now we solve for  by subtracting  from both sides, taking the cube root, and then adding :

 is our inverse function, 

Example Question #3 : Inverse Functions

  

What is  ?

Possible Answers:

Correct answer:

Explanation:

The question is essentially asking this: take  say that equals , then take , then whatever that equals, say , take . So, we start with ; we know that , so if we flip that around we know . Now we have to take , but we know that is . Now we have to take , but we don't have that in our table; we do have , though, and if we flip it around, we get , which is our answer. 

Example Question #4 : Inverse Functions

  

What is  ?

Possible Answers:

Correct answer:

Explanation:

Our question is asking "What is  of  of  inverse?" First we find the  inverse of . Looking at the question, we see ; if we flip that around, we get . Now we need to find what  is; that is an easy one, as it is directly provided: . Now we need to find . Again, this isn't given, but what is given is , so , and that is our answer. 

Example Question #5 : Inverse Functions

Over which line do you flip a function when finding its inverse?

Possible Answers:

You do not flip a function over a line when finding its inverse.

Correct answer:

Explanation:

To find the inverse of a function, you need to change all of the  values to  values and all the  values to  values. If you flip a function over the line , then you are changing all the  values to  values and all the  values to  values, giving you the inverse of your function. 

Example Question #6 : Inverse Functions

Find the inverse of this function: 

Possible Answers:

Correct answer:

Explanation:

To find the inverse of a function, we need to switch all the inputs ( variables) for all the outputs ( variables or  variables), so if we just switch all the  variables to  variables and all the  variables to  variables and solve for , then  will be our inverse function. 

turns into the following once the variables are switched:

the first thing we do is subtract  from each side; then, we take the natural log of each side. This gives us

Then we just add three to each side and take the square root of each side, making sure we have both the positive and negative roots. 

This is the inverse function of the function with which we were provided.

Example Question #1 : Inverse Functions

Please find the inverse of the following function.

Possible Answers:

Correct answer:

Explanation:

In order to find the inverse function, we must swap  and  and then solve for .

Becomes

Now we need to solve for :

Finally, we need to divide each side by 4.

This gives us our inverse function:

Example Question #1 : Inverse Functions

Find the inverse of .

Possible Answers:

Correct answer:

Explanation:

To create the inverse, switch x and y making the solution   x=3y+3. 

y must be isolated to finish the problem.

Learning Tools by Varsity Tutors