graphing a function and its inverse

[jshaziza]

f(x)=x^3+2

I am having trouble figuring out how to graph this since my book just shows me the graphing line but doesn't explain how they got those weird shaped lines. I know the inverse is the 3 sqrt of x-2. Thx to anybody who can tell me how they go about graphing these functions.

 

[pka]

 

[stapel]

f(x)=x^3+2

I am having trouble figuring out how to graph this...

Graphing should have been covered well before this point! :shock:

Have they taught you how to plot points yet? Or do we need to start there? Once you know how to plot points, and assuming you know how to evaluate functions, the rest is simple! :wink:

I know the inverse is the 3 sqrt of x-2.

Hm... Since you're referring to the cube root as "the 3 sqrt", I would guess that you haven't yet learned about radicals. This also should have been covered long before now....

Try the following for clarification:

. . . . .Google results for "x y plane" (for plotting points)

. . . . .Google results for "radicals"

. . . . .Google results for "evaluating functions"

. . . . .Google results for "graphing"

The above should serve to cover the gaps in what your class has covered, so you're able to interpret this exercise. Have fun!

Eliz.

 

[jshaziza]

Stapel don't be cute, I know all about radicals but I don't know how to put the different signs onto this forum, and about the graphing, is it about the same as graphing qaudratic functions where I pick some numbers for x and than figure it into the equation to get y?

 

[pka]

but I don't know how to put the different signs onto this forum,

You can begin by learning TeX or LaTeX.
Go to the pull-down tab "FORURM HELP" at the top of this page.

 

[stapel]

Stapel don't be cute

My apologies for my misunderstanding.

Since you are not wanting instruction on functions, radicals, or graphing, please reply with clarification regarding what you are wanting. If we all speak clearly, then perhaps you will suffer no further offense. :wink:

Thank you!

Eliz.

 

[Deleted member 4993]

... I know all about radicals ...

I have taken many many mathematics classes - did graduate work in highly mathematical subject - and am a practicing engineer - but I cannot say with your kind of certainity that I know ALL about any part of mathematics (starting with addition - my 3 year old cousin made that very clear to me - but that is another story)...

A little bit of humility will go a long way - specially when you are begging for free help...

 

[jshaziza]

SK you know I did not mean it that way, I felt stapel was making fun of me and saying I knew nothing of radicals, what I meant was that I knew my way around radicals. I don't know how he came up with me being terrible at radicals just because I didn't know how to translate the symbols unto this forum. As for the humility, if you look at all my posts, you will always see me thanking anybody whol helped me out. I do appreciate any help, however I don't appreciate being put down just for asking a simple question. Thx again for any help.

 

[stapel]

SK you know I did not mean it that way...

On what basis do you claim to "know" that others are able to read your mind and see what you intended? I would respectfully submit that this is not entirely fair of you.

It might be more productive if we could all try to clearly say what we mean, up front, in the first place, without making assumptions about or attacks on the motives or characters of others, should those others happen to offer help in unintended directions or make other honest mistakes.

Thank you for your consideration.

Eliz.

 

[jshaziza]

Stapel if you meant no offense with your statements than I apologize for my response. However I would still like to know how you came up with me not knowing anything about radicals just because I used the phrase 3 sqrt. In Karl's notes on the Forum Help it says for square root problems to write sqrt. So that is what I used, but how does that translate to me knowing nothing about square roots and that I should have learned it by now. I would hope I know at least a little bit about radicals if I am taking Algebra 2. But anyway, I don't want to make a big deal out of this, because it's not that important, as long as you didn't mean to purposefully insult me, I am again sorry for my comment. Now back to the real matter at hand. My question was whether use the same method to graph that formula as I would to graph a quadratic function, where I choose some values for x and then figure y out?And by the way I am very thankful for any help. Have a great day.

 

[stapel]

The fact that you are still referring to the cube root as "the 3 sqrt" strongly implies that you haven't yet encountered the cube root. Since you need to know about the cube root in order to complete the initially-posted exercise, you were provided with links to lessons explaining, among other things, how the cube root differs from the square root, both in calculations and in graphing.

Again, I apologize for having offended you by offering you these links. However, I'm afraid that, lacking an understanding of cube roots, it would be difficult, if not impossible, for me to figure out how to assist with this exercise. Sorry.

Eliz.

 

[jshaziza]

Stapel I know about cubed roots, so if you want to help me show me how you would write it down on this forum without Latex or whatever else you use, just use the symbols on your keyboard. And why can't you just answer my question on the graphing, all I asked you was if I would use the same method to solve that formula I gave you in the beginning of this topic, as I would to graph other functions.Thx.

 

[skeeter]

y equal to the cube root of x can be written as ...

y = cbrt(x)

or

y = x^1/3


to answer your last question, the graph of a function's inverse is symmetrical to the line y = x, as depicted in pka's graph.

you might also take a look at the following link for more info re: graphs of inverse functions ...

http://www.purplemath.com/modules/invrsfcn.htm



... is the horse dead?

 

[morson]

^ lol.