Problem on finding second derivative.

In summary: Remember to simplify, you can factor out a 2x from the numerator to get \frac{2x(x^2+12)}{(x^2-4)^3}. In summary, the function given is \frac{x}{x^2-4} and the first derivative is \frac{-x^2-4}{(x^2-4)^2}. The second derivative is \frac{2x(x^2+12)}{(x^2-4)^3} and it can be simplified by factoring out a 2x from the numerator. The simplified second derivative is \frac{2x(x^2+12)}{(x^2-4)^3}.
  • #1
jzq
55
0
I have a problem on finding the second derivative for this function:

[tex] \frac {x}{x^2-4} [/tex]

For the first derivative, I got:

[tex] \frac {-x^2-4}{(x^2-4)^2} [/tex]

Now here is where I am stuck! So far for the second derivative, I got this (Please check!):

[tex] \frac {-2x(x^2-4)^2-4x(-x^2-4)(x^2-4)}{(x^2-4)^4} [/tex]

I need the second derivative simplified! I know, it's an easy question. I may have lost my mind! :rofl:
Also please explain. Thanks!

BTW. I am new to this forum and just learned the latex system. It is very complicated. Took me a while just to write out the problems above. I guess I got to get used to it.
 
Last edited:
Physics news on Phys.org
  • #2
Those look good to me. Now all you need to do is simplify. That should be the easy step. You have a factor of [itex] (x^2-4)[/itex] that will divide out. You should be able to get it down to one term.
 
  • #3
Davorak said:
Those look good to me. Now all you need to do is simplify. That should be the easy step. You have a factor of [itex] (x^2-4)[/itex] that will divide out. You should be able to get it down to one term.
Is this what you got?:

[tex] \frac {2x^3+24x}{(x^2-4)^3} [/tex] or [tex] \frac {2x(x^2+12)}{(x^2-4)^3} [/tex]
 
  • #4
Looks good
 

1. What is the purpose of finding the second derivative?

The second derivative is used to determine the rate of change of a function's slope. It can provide information about the concavity, or curvature, of a function and can be used to find the maximum and minimum points of a function.

2. How do I find the second derivative?

To find the second derivative, you will need to take the derivative of the first derivative. This can be done using the power rule, product rule, quotient rule, or chain rule, depending on the complexity of the function.

3. What is the difference between the first and second derivative?

The first derivative represents the rate of change of a function, while the second derivative represents the rate of change of the first derivative. In other words, the second derivative shows how quickly the slope of a function is changing.

4. When is it necessary to find the second derivative?

The second derivative is often used in optimization problems, where the goal is to find the maximum or minimum value of a function. It is also used in curve sketching to determine the concavity and inflection points of a function.

5. Can I find the second derivative of any function?

Yes, the second derivative can be found for any differentiable function. However, the process may be more complex for certain types of functions, such as trigonometric or exponential functions, that require the use of special rules or techniques.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
816
  • Introductory Physics Homework Help
Replies
6
Views
881
  • Introductory Physics Homework Help
Replies
4
Views
550
  • Introductory Physics Homework Help
Replies
6
Views
267
  • Introductory Physics Homework Help
Replies
4
Views
664
  • Introductory Physics Homework Help
Replies
3
Views
694
  • Introductory Physics Homework Help
Replies
2
Views
696
  • Introductory Physics Homework Help
Replies
23
Views
335
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
2
Replies
64
Views
1K
Back
Top