## carlj0nes one year ago I need some help with creating some graphs in excel. Im not sure what data I need to input. Once posted I will attach pictures of the three questions I need to do the graphs for. What the question is I have been told I need to do for each solution, draw their corresponding graph and clearly label and annotate as follows to include axes, units and titles.

1. anonymous

@pooja195 @dan815 @nincompoop @ganeshie8

2. carlj0nes

first question

3. carlj0nes

Second question

4. carlj0nes

third and final

5. pooja195

im not sure o-o @dan815 @nincompoop help please!

6. anonymous

@michele_laino @jigglypuff314 @hero

7. Australopithecus

Do you have excel for windows or mac?

8. carlj0nes

windows

9. Australopithecus

Oh you are just graphing functions

10. carlj0nes

Im not sure. all I now is that I need to do this for each of the three questions. For each of these solutions, draw their corresponding graph and clearly label and annotate as follows to include axes, units and titles.

11. Australopithecus

Well I assume they are just asking you to graph the solution (function) to each of your problem. This should gives you a rough idea on how to use excel https://www.youtube.com/watch?v=ITgT3YPDeLs It is actually a fairly intuitive program to use. This shows you how to annotate a graph. https://youtu.be/AtWQA2YJ5O4?t=82

12. Australopithecus

You can set up equations similar to how you would write them in a calculator in excel, you click cells to represent variables though.

13. Australopithecus

Make sure that the graphs you set up follow any constraints set forth by the question

14. Australopithecus

If you have any questions or problems setting up the graphs in excel let me know

15. carlj0nes

The first hurdle is that im not sure what to put for the values for each of the questions

16. Australopithecus

Well if you are just trying to graph something you can use arbitrary x values

17. Australopithecus

I mean if they are only asking you to graph the function just use arbitrary inputs to show the shape of the curve (although make sure the inputs make sense with respect to the formula no negative time etc) that should be acceptable.

18. Australopithecus

As far as I can tell from your question, unless they gave you any other direction

19. Australopithecus

I recommend just using arbitrary inputs if it didn't specify what inputs to use. As at least that way you have something. You could also ask your instructor if that is fine as well.

20. Australopithecus

Just make sure your inputs make sense

21. Australopithecus

There should be more people on later, the youtube video links I provided should get you to where you need to go as far as graphing is concerned. Note: You can set up excel equations just like you would an equation into a calculator or computer. Just use brackets etc, your variables are just cells, the youtube video i provided show that though.

22. carlj0nes

Thanks for your help. Hopefully when they come on later they can assist with this.

23. Australopithecus

I am not sure what others will tell you that I have not though given the information you provided.

24. Australopithecus

I really recommend you look at the youtube videos I provided. For question 6 use arbitrary inputs from like -10 to 10, with interval of 1 that should be fine so, -10 -9 -8 etc

25. Australopithecus

anyways I have to go, I highly recommend that you just graph them now using excel (watch the video) using arbitrary inputs. Then if you find that you need to use specified inputs (for some reason the question wasnt complete, or you are missing information) then you can easily change the values in excel no problem

26. Australopithecus

the two videos I provided should suffice for you. I recommend using smooth curve to graph the equations.

27. Australopithecus

Anyways let me know if you have any problems using excel.

28. Michele_Laino

first question: The solution of your differential equation is: $\Large y\left( x \right) = {c_1}{e^{2x/3}} + {c_2}x{e^{2x/3}} + {y_p}\left( x \right)$ in order to find the correct form of y_p, you have to try this substitution: $\Large {y_p}\left( x \right) = A{x^4} + B{x^3} + C{x^2} + Dx + E$ where A, B, C, D, and E are real coeeficients

29. Michele_Laino

after as imple computation, I got: $\Large \begin{gathered} {y_p}\left( x \right) = A{x^4} + B{x^3} + C{x^2} + Dx + E = \hfill \\ = \frac{x}{2} + \frac{5}{4} \hfill \\ \end{gathered}$

30. Michele_Laino

coefficients*

31. Michele_Laino

second question: here we can rewrite your ODE as follows: $\Large \frac{{dV}}{{dt}} + \frac{1}{{RC}}V = \frac{E}{{RC}}$ and the corresponding solution is given by the subsequent expression: $\Large \begin{gathered} V\left( t \right) = {e^{ - t/RC}}\left( {k + \int {\frac{E}{{RC}}{e^{t/RC}}dt} } \right) \hfill \\ \hfill \\ V\left( t \right) = k{e^{ - t/RC}} + E \hfill \\ \end{gathered}$ where K is the integrtion constant, namely: $\Large V\left( 0 \right) = k$

32. Michele_Laino

third question the solution of your differential equation, is: $\Large x\left( t \right) = {c_1}{e^{5t + i3t}} + {c_2}{e^{5t - i3t}}$ where c_1 and c_2 are two arbitrary real constants. Now I can rewrite that solution as below: $\Large x\left( t \right) = {e^{5t}}\left\{ {{c_1}\cos \left( {3t} \right) + {c_2}\sin \left( {3t} \right)} \right\}$ now using your initial conditions, we get: $\Large \begin{gathered} {c_1} = 2 \hfill \\ {c_2} = - \frac{{10}}{3} \hfill \\ \end{gathered}$