domains of functions: f(x) = 2x/(x2 - 16)

[marshall1432]

i have just one question right now. i was given a set of questions asking me to find the domain and range of a graph and that was perfectly easy for me to do, however i came across this problem.

What is the domain of the function f(x) = 2x/(x2 - 16)? Give your answer in interval notation, using INF for infinity.

i know how to set it up: 2x/(x+4)(x-4)

After that I do not know what to do. I know that on a graph the domain is the left most value and rightmost value and the range is the lowest bottom value and highest top value. can anyone help? thanks

 

[stapel]

You might want to start by reviewing some of the previous explanations you've received regarding domain and range:

. . . . .Domain and range: first thread

. . . . .Domain and range: second thread

To reiterate, the "domain" is all allowable x-values. To find the domain of a given function, one customarily finds x-values that will not work, and then gives the domain as being all other x-values.

To do this, one checks asymptotes (such as for logarithms, square roots, etc) and denominators (for division by zero).

Eliz.

 

[marshall1432]

ok sorry for not understanding. i wasnt like most people and born with the gift of math and everyone can stop rubbing it in my face every time i get on here and try to ask for help. it's fine, whatever. from now on, if you arent going to help me then dont say anything at all.

 

[stapel]

ok sorry for not understanding. i wasnt like most people and born with the gift of math and everyone can stop rubbing it in my face every time i get on here and try to ask for help. it's fine, whatever. from now on, if you arent going to help me then dont say anything at all.

I'm not sure to what private message -- or whatever -- the above is your response...? Since I'm not aware of any other users attacking you (though no few have been attacked by you), I'm not sure what you mean by "rubbing your face" in whatever...?

If you aren't wanting tutoring help ("don't reply", etc), then it might be better not to request it. If you were expecting "help" to mean just giving you the answers, then I apologize for the miscommunication: Most legitimate tutors don't do this, instead opting to help students learn, so they can succeed on their own.

If, on the other hand, your above reply (and please don't fake-edit this thread to remove your reply, and then call us liars again) was a mistake that you regret, and you'd like to try to learn this material, then please review the explanations and worked examples you've been given earlier, and then attempt to follow the instructions provided here.

Thank you for your consideration.

Eliz.