# How solve the instantaneous rate

1. Feb 28, 2008

### janemba

how solve a limit

do anyone how do you solve a limit how work because im beginning this heres one problom

y= $$\overline{}2x$$
x+1

Last edited: Feb 28, 2008
2. Feb 28, 2008

### sutupidmath

$$y=\frac{2x}{x+1}$$ is this what u wrote?

And you want to find the instantaneous rate of change, right?

Any thoughts from your side on how to do it?
We are not supposed to do your homework!

EDIT: to find the instantaneous rate of change you need to evaluate the limit
$$lim_{h\rightarrow\ 0}\frac{f(x+h)-f(x)}{h}$$ which actually is the derivative of that function! Assuming that this fucntion represents the velocity!

Last edited: Feb 28, 2008
3. Feb 28, 2008

### janemba

yes

yes it is and yes im trying to find the instantaneous and it is not homework i want to learn how you solve it step by step

Last edited: Feb 28, 2008
4. Feb 28, 2008

### sutupidmath

Have you given any thoughts so far on how to do it??? SHow us what have u done so far, so someone here might point u on the right direction. People here won't just give you the answer, especially here at the Homework Forum!

5. Feb 28, 2008

### janemba

Um

the truth is im 14 and i want to be the smartest person on earth and want to be physics professor so i figure you have to learn calculus before going into QUANTUM PHYSICS

6. Feb 28, 2008

### sutupidmath

Well, are u trying to find the limit or the instantenaous rate of change? Because i do not see any limits here?? Can you post the whole question first?

7. Feb 28, 2008

### sutupidmath

I do not think quantum physics is taught at high school is it?
I envy you for trying to deal with these things at this age! well, i must ask you again, are you trying to find some kind of limits, or what? Because you edited your original post, so i do not know what exactly are you looking for! then i might try to point you on the right direction!

Last edited: Feb 28, 2008
8. Feb 28, 2008

### janemba

in college

no way its taught in college but you start learning about physics

9. Feb 28, 2008

### janemba

how

how do you evaluate instantaneous rate of change and where is the derivative

10. Feb 28, 2008

Hi there! Welcome aboard! I too admire your enthusiasm. It is hard, though, to tell where to start, especially without knowing your background in mathematics. If you have a strong background in algebra and geometry, that will definitely help.

I would suggest searching around online first like http://en.wikipedia.org/wiki/Derivative" [Broken] and seeing what you can extrapolate for yourself. Then come on back here to PF and show us exactly where you are having trouble.

Do you understand what the derivative means? If not, do a little reading in Wiki or elsewhere and come back with questions.

Hope to hear from you soon!

Last edited by a moderator: May 3, 2017
11. Feb 28, 2008

### janemba

I

I Only Know The Power Rule To Find Dervitives But Geometry I Get

12. Feb 28, 2008

Google "the quotient rule" and see what you get. Come back with questions.

13. Feb 28, 2008

### janemba

is that how you do it because i Google the quiotent rule but just didn't know what it meant

\frac{d}{dx}f(x) = f'(x) = \frac{h(x)g'(x) - g(x)h'(x)}{[h(x)]^2}.

14. Feb 29, 2008

### sutupidmath

The deal is that if you really want to learn this material, then you have to start from something that is really elementary, and do things one step at a time! so if you have no idea what a limit is, and what a derivative is, then my advice is buy a book that is really elementary but that will introduce you to some quite important concepts!

15. Feb 29, 2008

### Sleek

I'd recommend reading the theory behind derivatives as rate of change, and it's geometric significance. And one more thing, be thorough with the concept of limits (not just some list of formulas), so that you can understand the "first principle" of derivatives and other elementary concepts.

Here is a link to a complete video series on Calculus by Houston University,

http://online.math.uh.edu/HoustonACT/videocalculus/

Regards,
Sleek.

16. Feb 29, 2008

### janemba

yea

i have a book about calculus its called super review calculus all you need to know but its just confusing

17. Feb 29, 2008