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  1. M

    A minor difficulty in PMF

    I got a minor stuck here... please help me. Ok the stat problem is ... a mail order business has 9 phone lines and x is the number of line in use at a specified time. pmf of X is given: x 1 2 3 4 5 6 7 P(x) .1 .15 .2 .25 .2 .06 .04 Calculate the probability of certain events I...
  2. M

    SOme help with intergration by parts,

    SOme help with intergration by parts, plz [b]1. Find: \int e^x cos (x) dx The Attempt at a Solution I tried using integration by parts - what we are working on... all these 3 possibilities: u = cos x, u= e^x, u = e^x cos(x) And the \int vdu are, respectively: 1. \int e^x sin(x) dx...
  3. M

    Need help: integration by substitution.

    Hello all, how are you? we are currently working on integration by substitution, what do you guys think about the way i solved this one: Find: \int \frac{(t+1)^2}{t^2} dt My solution: \int \frac{(t+1)^2}{t^2} dt = \int 1dt + \int \frac{2}{t} dt + \int \frac{1}{t^2} dt = t +...
  4. M

    Definite Integral prob

    Daniel, yeah thanks for the code... i meant k\int_{0}^{3} e^{-0.25 x}{}dx =1 HallsofIvy, Uh... Thats the same word from the problem in the book... and yes, thats the integral from 0 to 3... Im not sure I know about the total integral.... Sorry about the confusion.
  5. M

    Definite Integral prob

    Sorry, my LaTeX code looks bad.
  6. M

    Definite Integral prob

    Hello, Okay so I was given a density function: f(x) = 2e^(-0.25x) The problem asks for the value of Pr(X < or = 3) I first figured out the probability density function first by let \int (3,0) k.25e^(-.25x) = 1 And figured out that k = .45 and continue solving my...
  7. M

    Around the corner problem?

    "Around the corner" problem? Hey, I got this assignment from my class... it asks for the maximum length for a bar in order to get it through a corner created by 2 hallways... Im provided with the width of the 2 hallways and that's it. Can someone gimme a suggestion? Thanks Nam
  8. M

    Need some suggestions.

    Hey... Im kinda got stuck with this problem... can you guys give me a hint or something... Problem says: The tangentline to the curve y=1/3 x^3 - 4x^2 + 18x + 22 is parallel to the line 6x - 2y = 1 at 2 points on the curve... find the 2 points. Well I was thinking about writing the...
  9. M

    Ice Cream and evolution.

    Oh hello This's just strange. We did a small project "Making ice-cream" You know, put milk and sugar and vanilla into a zimploc, place the pack into a bigger one stuffed with ice and salt. We've luckily gone through the questions he asked. But the last question just doesn't make sense to me...
  10. M

    How to distinguish linkage and crossover?

    I really dunno how to distinguish beween 2 things, it's based on the ratio right? Thanks
  11. M

    New to genetics

    Well, I'm also a new one to genetics. I'm at Genetic linkage and crossover... I think I can understand the stuff.. but I can't find exercises to apply... What;s your idea? Thanks
  12. M

    Website for genetic interaction?

    Excuse me, I'm learning about the genetic interaction and I think I can get pretty much explaination in the Internet but Google didn't seem to be really helpful now. So please suggest me some sites on genetics and I'll try out! Thanks alot!
  13. M

    People who can let electricity flows through their bodies

    So why there're ppl who can let the electricity flow thru them while others can't?
  14. M

    People who can let electricity flows through their bodies

    Well, I've heard about some people who can let electricity flows through their bodies without any serious damage. Is there any sciebtific reason or theory for this? Is that the resistance f them 0 or nearly so? What do you think?
  15. M

    Related to Emf

    Please be patient, I'm sure somebody will help you. :)
  16. M

    Absolute equation problems.

    Okay, thanks Dextercioby. Viet dao, you meant that I compute incorrectly? Hmmm let me do it again. Or, we can 'break out' the absolute by devide into two situation: x-1 >= 0 or x-1 <0 it's long, but not so confusing.
  17. M

    Absolute equation problems.

    Why? So, is my solution wrong? Thanks
  18. M

    Absolute equation problems.

    Hello, Well, I have the equation: x^2-2x-m|x-1|+m^2=0 (1) They ask me what m is so that the equation has solution(s) Well, I let t=|1+x| and solve the problem with t (no more x) and I have the last equation: t^2-mt+m^2-1=0 (2) in order that (1) has solution(s), (2) must have solution(s) t...
  19. M

    Basic Chemistry problem

    Ah, by the way, We have: If \Delta =0, the subtance is not 'full' so; it has no \pi_{cc} linkage, no 'cycle. If \Delta =1, the subtance has 1 \pi_{cc} linkage OR 1 'cycle' If \Delta =2, the subtace has 2 \pi_{cc} linkages OR 1 \pi_{cc} linkage + 1 'cycle' OR 2 'cycles' So, what is this...
  20. M

    Basic Chemistry problem

    Well, hello! I was informed a new formula. As a non-native, I can't give out the definitons, I hope that you can help me call some. Well, here is the formula: \Delta=\frac{2+\Sigma n_i (V_i-2)}{2} Well, as far as I can say, \Delta here is equal to the total of the linkage C=C+ number of...
  21. M

    Need help on Ohm's Law

    Well, okay, Thanks! Thanks for all of your time and help!
  22. M

    Need help on Ohm's Law

    Excuse me, still, I don't know what for? Please explain for me. Thanks! btw, if we figure the another way, as thru R3 and R4, is it the same? Thanks
  23. M

    Need help on Ohm's Law

    Oh thanks, I got it, it's U_{MN}=4V Thanks alot!
  24. M

    Need help on Ohm's Law

    Ohh, sorry, I'm so clumsy, I didn't mean to draw a straight line connecting M and N, there was nothing connecting them at all. yes, they meant to cross the resistances. And that's helped. Thanks! BTW, I got difficulty when I need to go down for the next line, what's the syntax in LaTex for...
  25. M

    Need help on Ohm's Law

    Well, I'm quite idle in Lunar New year's holidays so I decide to do some exercises on Physics, I got stuck when solving the problem, then I tried with the suggestion on my text book, but still, I don't understand the problem, please help me out! btw, sorry, something has gotten on LaTex or I'm...
  26. M

    Some special consequences from the limits of e: need a little help

    Hmm... yeah, the basic consequence \lim_{x\rightarrow0}\frac{ln(1+u)}{u}=1
  27. M

    Some special consequences from the limits of e: need a little help

    Uhmm... alright! Just imagine that sinx = \alpha Then the thing above is equal to: \lim_{x\rightarrow0}\frac{ln(1+\alpha)}{\alpha} (*) Then, this limit is a consequence limit of e: \lim_{x\rightarrow\infty}(1+\frac{1}{x})^x = e So. (*) =1
  28. M

    Some special consequences from the limits of e: need a little help

    Hmmm... So far, I've done it. But I think tis way is better: \lim_{x\rightarrow0} \frac{ln(1+sinx)}{x} =\lim_{x\rightarrow0} \frac{ln(1+sinx)}{sinx} . \frac{sinx}{x} =1.1 = 1 Is it right?
  29. M

    Some special consequences from the limits of e: need a little help

    Okay, thanks! PS: Thanks for telling me about LaTex! It's cool! I'm learning it!
  30. M

    Some special consequences from the limits of e: need a little help

    Well, I got it as lim (x->0) of [(1+sinx)^(1/x)]
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