Domain of Rational Function: What is the domain of the given rational function?

[mathdad]

Find the domain of the rational function.

y = (6x^2 + 11x + 4)/(3x + 4)

Solution:

Let denominator = 0 and solve for x.

3x + 4 = 0

3x = -4

x = -4/3

This means the domain is any real number except for
x = -4/3.

When x = -4/3, the denominator becomes 0, which is undefined.

Correct?

 

[kaliprasad]

Find the domain of the rational function.

y = (6x^2 + 11x + 4)/(3x + 4)

Solution:

Let denominator = 0 and solve for x.

3x + 4 = 0

3x = -4

x = -4/3

This means the domain is any real number except for
x = -4/3.

When x = -4/3, the denominator becomes 0, which is undefined.

Correct?

Right.

You have got so many posts now you should start posting in latex. Then people shall not struggle to find the equation that you have mentioned.

you can find the latex guide in the link below

http://mathhelpboards.com/showthread.php?1142-MHB-Latex-Guide-PDF

 

[mathdad]

Right.

You have got so many posts now you should start posting in latex. Then people shall not struggle to find the equation that you have mentioned.

you can find the latex guide in the link below

http://mathhelpboards.com/showthread.php?1142-MHB-Latex-Guide-PDF

I do not have a computer, laptop, or tablet. Some of the symbols needed to use latex are not in my Samsong J7 phone. All my questions are posted via cell phone keyboard which is very limited.

 

[MarkFL]

I do not have a computer, laptop, or tablet. Some of the symbols needed to use latex are not in my Samsong J7 phone. All my questions are posted via cell phone keyboard which is very limited.

What symbols are you lacking? Creating $\LaTeX$ markup doesn't call for any special characters that I can think of, and the vast majority of the symbols/commands used can be found in our Quick LaTeX tool. :D

 

[mathdad]

My question is about domain not latex but I will try the Quick LaTex tool box occassionally.

 

[MarkFL]

My question is about domain not latex but I will try the Quick LaTex tool box occassionally.

The issue raised concerns the readability of posts with mathematical expressions formatted in plain text vs. those formatted using $\LaTeX$. For all but the simplest of expressions, trying to read those formatted in plain text becomes difficult, adding an extra burden on those trying to provide help. Those seeking help, should in general, try to take steps to present their questions in the best way possible.

Now, it is quite understandable that a new user may not be familiar with $\LaTeX$, but after hundreds of posts, we do kind of expect a user to make the effort to learn how to use of $\LaTeX$. It's not an absolute requirement, but those providing help do appreciate easier to read posts and the effort shown. :D

 

[mathdad]

I tried using Quick LaTex but the image did not show up.

Give me an example.

How do I use QUICK LATEX to create an image for

y = x^3

y = x^(1/5)

y = e^x

Can you write the steps down? I do not think this will work on my cell phone.

 

[MarkFL]

I tried using Quick LaTex but the image did not show up.

Give me an example.

How do I use QUICK LATEX to create an image for

y = x^3

y = x^(1/5)

y = e^x

Can you write the steps down? I do not think this will work on my cell phone.

On the toolbar above where you enter your post content, you should see a button with a $$\sum$$ symbol on it. Click that to generate the $$$$ tags. Your cursor will be located in between the tags. Now you are ready to enter your LaTeX code. Type y=x^3 so that you have:

$$y=x^3$$

and your post will look like:

$$y=x^3$$

 

[mathdad]

For y = x^(1/5),

$$y={x}^{1/5}$$

- - - Updated - - -

For y = e^x,

$$y={e}^{x}$$

 

[Greg]

$$y = \frac{6x^2 + 11x + 4}{3x + 4}$$

Follow-up question:

What does the graph of $y$ look like?

 

[MarkFL]

$$y = \frac{6x^2 + 11x + 4}{3x + 4}$$

Follow-up question:

What does the graph of $y$ look like?

It reminds me of "Abacab" by Genesis...hehehe. :D

 

[mathdad]

I forgot how to graph rational functions. I usually go to wolfram for all my graphs.

 

[mathdad]

$$y = \frac{6x^2 + 11x + 4}{3x + 4}$$

Follow-up question:

What does the graph of $y$ look like?

I typically use wolfram for all my graphs. I am more concerned with computation than graphing by hand.

 

[MarkFL]

I forgot how to graph rational functions. I usually go to wolfram for all my graphs.

Hint: Try factoring the numerator...:D

 

[mathdad]

Mark,

My concern is computation, especially becoming an "expert" in terms of translating word problems to equations. I use wolfram for all my graphs. Remind me to share my Bank One story.

 

[MarkFL]

Mark,

My concern is computation, especially becoming an "expert" in terms of translating word problems to equations. I use wolfram for all my graphs. Remind me to share my Bank One story.

Yep, knowing Greg, he was likely just trying to pile on some extra "busy work" rather than attempting to take you down a path that might lead to a better understanding of certain types of rational functions. (Giggle)

 

[mathdad]

I love graphs but there is no need to master the art of graphing by hand, especially since I am not in any particular math class. I am simply reviewing precalculus. I took precalculus in the Spring semester 1993 at Lehman College as an elective course and got an A minus. I have seen hundreds of rational functions but computation is my main concern. I do not care about graphing by hand as much as I needed to learn this skill in 1993.