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  1. L

    I got one problem

    Homework Statement integral of csc^3(x)cot(x) Homework Equations I tried using trig identity 1+cot^2(x)=csc^2(x) but I got result where I canceled my indegrals. The Attempt at a Solution I tried to substitute the above mentioned indentity for csc^2 but I end up getting -cscx +...
  2. L

    I got two problems

    Yup. Today in class I realized how stupid was what I wrote here last night. :blushing: I guess, for some reason, I assumed that because there is that 2x regular cos formula for derivative doesen't apply. Thanks for help. I appreciate it.
  3. L

    I got two problems

    Got the first one too. Thanks for the help. It would help if we actually learned the derivative of cos(2x), but since we didn't and it is nowhere in the book I just assumed we don't need to use it. Well...I certainly do feel better now.:smile:
  4. L

    I got two problems

    I solved the second one but the first one is still killing me.
  5. L

    I got two problems

    Homework Statement I need to find the integral of (e^3x)cos(2x) Homework Equations The Attempt at a Solution I tried using different trig identities for cos(2x) to get a better equation and then tried to do few versions using the integration by parts but they all kept getting...
  6. L

    Find the derivative of the inverse function

    Hmmm...But isn't the range of f(x) (-infinity, infinity)?
  7. L

    Find the derivative of the inverse function

    So I need to find the derivative of the inverse function. I know that f is one-to-one and is continous. Also I know that f'(x)=1+[f(x)]^2. I found the inverse writing my equation like f(x)=x+(1/3)[f(x)]^3 then I switch the variables and get that my inverse function=(1/3)x^3 - x. Then I just take...
  8. L

    Find ln using differentials.

    Alright, so I need to find f(x+h) which would be f(10+0.3), with 0.3 being change in x. Using my notes...I see that I could make my equation look like f(x+h)=f(x+(1+(h/x))), where I would break it so that it looks like f(x+h)=f(x)+f(1+(h/x)). I would then substitute 2.30 for f(x), 0.3 for h and...
  9. L

    Find ln using differentials.

    So the problem says "Taking ln10=2.30 estimate ln10.3 using differentials." The only thing I thought of doing was to set an integral from 1 to 10.3 with 1/x being the equation I integrate, but I'm not sure if that is right. Any help?
  10. L

    Purdue vs. Illinois

    Well, I guess I'll have to become independent and find myself a job quickly. Damn, I told my parents to move to Illinois, but for some reason they like NC. This sucks!
  11. L

    Purdue vs. Illinois

    Well, a just got into the University of Chicago, so I have some decisions to make. I'm still the closest to Illinois, because it has engineering and from what I hear here it is a nice school (I'm Serb so drinking part is a big plus in my world), but you know Fermi Lab and 26 Nober Prize Winners...
  12. L

    Would a 3.6ish GPA average (maybe it will be higher when i end 12th

    Well you seem to be pretty bright guy, so just keep up the good work, and take as many AP courses as you can, because any university likes to see someone work hard. The fact that you came from Colombia and wl help you a lot.
  13. L

    Would a 3.6ish GPA average (maybe it will be higher when i end 12th

    No, I'm Serbian from Bosnia, where we had a nasty civil war. But still our situations are very similar. :smile:
  14. L

    Would a 3.6ish GPA average (maybe it will be higher when i end 12th

    Well it depends. Take my advice because I am in very similar situation as yourself. I came to U.S. 3 years ago, and went from ESL I to AP English IV in 2 years, also went from Algebra I to Calc in about 2 years. My GPA is something like 2.9 WEIGHTED and I still got into the University of...
  15. L

    Purdue vs. Illinois

    Yeah, I will visit both of them by the May 1.
  16. L

    Purdue vs. Illinois

    Well my problem with electronics is that the stuff you do is small and you don't see much, while the power engineering is a lot about the generators, and power plants, and big stuff. I think it is fair to say that I'm more interested in the physics of electricism and electromagnetism, but I...
  17. L

    Purdue vs. Illinois

    I didn't visit any of the two cities so I cannot make a judgment on that, but in any case academics is what I'm primarly interested in.
  18. L

    Purdue vs. Illinois

    Hi, I got accepted to Purdue and University of Illinois at Urbana-Champaign, both in Electrical Engineering. Now it it would be time to decide which one to pick, and I have some trouble doing that. I mean I'm mostly interested in studying Power Engineering and maybe minor in physics. So I would...
  19. L

    How can I get motivated/How do I know if I am learning everything I need to learn?

    Wow. This is something! Thanks a lot for posting this.:smile:
  20. L

    The problem of TOKAMAK

    Here is a video of Tokamak. http://www.jet.efda.org/pages/content/fusion2.html [Broken]
  21. L

    Increasing Our Pay.

    No doubt, however there are a lot more doctors than physics professors.
  22. L

    Increasing Our Pay.

    Trust me doctors have to study A LOT! I don't know if you ever saw their anatomy books and how detailed that crap is. I would bet that it takes just as much studying to become a doctor as to become a Physics Profesor. Lawyers? Well in my oppinion they are an important part of our society since...
  23. L

    I need some help.

    Oh I see. I guess I shouldn't have assumed that it is a second derivative. Thanks for the help.:smile:
  24. L

    I need some help.

    The problem says that if y=e^nx, then d^ny/dx^n=? I got that the result is n^2e^nx, but it is not among the offered choices. Can someone tell what did I mess up? Thanks.
  25. L

    Solving a Real-Valued Differentiable Function Problem

    O yeah I forgot. I got the a) part easily. Others I can't do.
  26. L

    Solving a Real-Valued Differentiable Function Problem

    Alright, here is the problem. For all real numbers x, f is differentiable function such that f(x)=f(-x). Let f(p)=1 and f'(-p)=5, for some p>0 a) Find f'(-p) b) f'(0) c) If L1 and L2 are lines tangent to the graph of f at (-p,1) and (p,1) respectively, and if L1 and L2 intersect at...
  27. L

    Studying Thinking of studying physical sciences

    That is why one should also get degree in engineering and then make a decent money if one fails in getting PhD.
  28. L

    Studying Thinking of studying physical sciences

    I have similar problems. My parents support me in whatever I choose but they expect too much. My dad is electronics technician so we kinda have similar interests. I always did better in social sciences, I'm even in an academic team, and last year I was in an allstar team, but I can't deal with...
  29. L

    Extremely discouraged by this one guy

    Personaly I think that you just got lazy. It is not so much about the talent as it is about the hard work.
  30. L

    Really challenging IQ test

    Thanks for test. I got 122, but I just wrote some crap for the word adding problem. It was too hard. Anyway, not bad fom me.:smile:
  31. L

    Can I Major in Math, Physics, Chemistry & Eng. in 4-6 yrs at a Good University?

    I understood you but I was actually quoting your comment about Tesla but adressing bomba. My bad, and yeah we have the same point.
  32. L

    Can I Major in Math, Physics, Chemistry & Eng. in 4-6 yrs at a Good University?

    He did that but it took not only the fact that he was genius, but also 15 hours of studying a day. I know a guy who is going into medical school and electrical engineering at the same time, but he studies all day, every day, last 5 years. Double majoring is more than enough, and I think that if...
  33. L

    I am failing my 1st year physics

    I thought you might be my countryman, so I said "It's going to be better".
  34. L

    I am failing my 1st year physics

    Bice bolje! Yeah, If you can do Calculus you can do Newtonian Mechanics! It might take some work, but it is definatrely not impossible.
  35. L

    Failing math

    Don't drop it to regular class. From my experience I can tell you that math is not much different, but teachers are usually better in honors classes, so are people around you, which can be very important. Try tutoring, and make sure you pay attention on class. Good luck!
  36. L

    Range problem

    For y values. They teach us to call x-values domain.
  37. L

    Range problem

    5^sqrt(7). If x=sqrt(2)/2, then I get F(x)=1
  38. L

    Range problem

    f(x)=5^sqrt(2(x^2)-1) I got that range is (1, to infinity) Is it correct?
  39. L

    Could you check this please

    It does. Thank you so much. :smile:
  40. L

    Could you check this please

    So I get f(x)^-1=e^(X^2-20) and f(x)^-1=e^x^2
  41. L

    Could you check this please

    So for others I just change ln to exp?
  42. L

    Which is better ?

    Japan, seems like cool place, but dimensions of their homes, and cars, and pretty much everything are just to small for me.
  43. L

    Could you check this please

    f(x)=e^cosx equation for the axis of symmetry? I got x=pi f(x)=ln(x^2 - 20) describe symmetry?? I got symmetric arround y axis. inverse?? I got y=sqr of ((x/ln) +20) f(x)=ln(x^2) Inverse? I got y= sqr of (x/ln)
  44. L

    Schools Do you guys work while attending University?

    Well my experience with work was pretty bad. Not academically but phsycologically. That is probably just me. I'm somehow alergic to work, and I would be very nervous when I have to go to work. I just hated it. Customers would never stopp coming. Yall should have seen my face when I quit. That...
  45. L

    Testing I got question about the new SAT

    Does anyone know what are minimum scores for University of Illinois at Urbana Champaign, North Carolina State University, and Purdue?
  46. L

    Some quick calc questions

    Well e^-t x e^t is same as e^t-t so It should be e^0=1. I haven't started on Integrals yet.
  47. L

    I got a question.

    Let's say that somehow a car moved with speed greater than the speed of light, would that mean that time is going backwards?
  48. L

    What to do with my life

    Damn. I hope I'm more excited about my career once I graduate. If it is not a problem could you tell me how did you decide to study something you hate so much now? Good luck man! Don't give up!
  49. L

    Nigerian Who Really Needs A Better Science Facility

    It is not 1600 anymore. Now it is 2400.
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