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Thread: Scary Calc. Question.... Any help greatly appreciated

  1. #1
    Senior Member yankeekd25's Avatar
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    Scary Calc. Question.... Any help greatly appreciated

    A population gorws according to the equation P(t)= 6000-5500e^-0.159t for t> or equal to 0, t measured in years. This population will approach a limiting value as time goes on. During which year will the population reach half of this limiting value?


    (A) Second
    (B) Third
    (C) Fourth
    (D) Eighth
    (E) Twenty-ninth

    What is a limiting value?
    Age: 19 Height: 5'11'', Weight: 185 BF: ~14-16%

  2. #2
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    Take the limit as t goes to infinity. The exponential term goes to 0, leaving you with 6000.

  3. #3
    Senior Member shootermcgavin7's Avatar
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    And if you need additional info from what special K said, just take half of 6000 and solve the equation for it. You can either use logs or just plug & chug since you have multiple choice.

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    Senior Member yankeekd25's Avatar
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    Quote Originally Posted by shootermcgavin7 View Post
    And if you need additional info from what special K said, just take half of 6000 and solve the equation for it. You can either use logs or just plug & chug since you have multiple choice.

    I got A. Im assuming thats right...
    Age: 19 Height: 5'11'', Weight: 185 BF: ~14-16%

  5. #5
    Wrecker of Homes d'Anconia's Avatar
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    Wait, I don't think this is really a calculus problem. Looks more like plain algebra to me.
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    Deadlift........?.....................315x5...............435x5
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    Quote Originally Posted by d'Anconia View Post
    Wait, I don't think this is really a calculus problem. Looks more like plain algebra to me.
    limit as t approaches infinity....looks like calc to me. Maybe "pre-calculus". Same ****, different pile.

  7. #7
    cakin Cirino83's Avatar
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    the answer is F

  8. #8
    chuck norris smitch250's Avatar
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    ive taken up to calc 3. yea it was fun. and yea we talked about stuff like that in calc. so id consider it a calc question.
    bench: 240
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    height:6'
    weight:183 (12%bf)

  9. #9
    Senior Member shootermcgavin7's Avatar
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    Quote Originally Posted by yankeekd25 View Post
    I got A. Im assuming thats right...
    Based on a quick run through my calculator, I think your assumption may be faulty.

  10. #10
    Senior Member yankeekd25's Avatar
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    what did you get then?
    Age: 19 Height: 5'11'', Weight: 185 BF: ~14-16%

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    From now on, just go here: http://www.sosmath.com/CBB/index.php

  12. #12
    Wrecker of Homes d'Anconia's Avatar
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    God damn it. The limit is 6000 so plug in 3000 for P(t) and solve for T and you get...
    t = 3.81
    SO during 3.81 years you are on the FOURTH year. So 'C' should be correct and that makes yankeekd25 and Cirino83 are incorrect (Ha, just had to screw with you guys).

    And yes I used my graphing calculator because why else would I ****ing buy it and not use it?

    Damn your calc problem thread has been bugging me all day. DONE! FIN! Somebody lock this thread.

    Sadly enough the first two replies explained how to solve it quite well.
    Last edited by d'Anconia; 04-12-2007 at 09:04 PM.
    ...........||High School||.....||July '05||.......||January '09||
    Bench.........225x1...............275x1.................?
    Squat...........?.......................?....................365x5
    Deadlift........?.....................315x5...............435x5
    Weight........180...................192...................185
    BF%.............?......................12.....................12
    Time to Get Ripped
    Pictures of Me

  13. #13
    Senior Member yankeekd25's Avatar
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    thank u guys. i didnt mean to bug ya... just needed a little help.
    Age: 19 Height: 5'11'', Weight: 185 BF: ~14-16%

  14. #14
    Senior Member shootermcgavin7's Avatar
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    fatrb needs to calm down.

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    It seems like every math problem thread gets 10+ more replies than are necessary.

  16. #16
    You stay classy San Diego. Ron Burgundy's Avatar
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    Quote Originally Posted by d'Anconia View Post
    Wait, I don't think this is really a calculus problem. Looks more like plain algebra to me.
    Calc is all about integration and deriving, other than knowing the rules of both it's plane algebra.
    I am SO glad I'm female.
    Seriously - I had NO IDEA it was this complicated.
    I just tell my husband he makes love like a God, feed him a steak, and I'm done for the day. Super easy.

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    Quote Originally Posted by Ron Burgundy View Post
    Calc is all about integration and deriving, other than knowing the rules of both it's plane algebra.
    Is that a pun?

  18. #18
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    he probably didnt mean it to be. That is calculus because the formula to find the exponential growth/decay can be derived from something or other. I just covered it in class a few weeks ago, but i was asleep so i don't remember fully why it has to do w/ calc.
    Been out the game for a little while, but jumpin back in

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    Quote Originally Posted by Ron Burgundy View Post
    Calc is all about integration and deriving, other than knowing the rules of both it's plane algebra.
    This problem involves taking a limit. Both the derivative and the integral operations are obtained by taking limits. That is why this problem could be classified as a calculus problem.
    Last edited by SpecialK; 04-13-2007 at 05:42 PM.

  20. #20
    Wrecker of Homes d'Anconia's Avatar
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    Quote Originally Posted by Wiki
    [Calculus] extends [analytical geometry] by introducing the concept of the limit which allows control over arbitrarily small and arbitrarily large numbers.
    While I may have been right about finding the answer, it looks like Ron and I are *technically* wrong in that limits are considered part of calculus (if we're going by Wiki's definition).
    ...........||High School||.....||July '05||.......||January '09||
    Bench.........225x1...............275x1.................?
    Squat...........?.......................?....................365x5
    Deadlift........?.....................315x5...............435x5
    Weight........180...................192...................185
    BF%.............?......................12.....................12
    Time to Get Ripped
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  21. #21
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    you don't actually have to take a limit to get the answer lol
    Been out the game for a little while, but jumpin back in

  22. #22
    Wrecker of Homes d'Anconia's Avatar
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    But then how would you know when you're at half of the maximum? Even if you don't write it on paper you have to look at it and calculate where the function would go when 't' goes toward infinity. That by definition I would think is considered taking the limit since you can't mathematically plug in infinity for 't'.

    Anyway you guys are making me feel like a mentally masturbating nerd right now.
    ...........||High School||.....||July '05||.......||January '09||
    Bench.........225x1...............275x1.................?
    Squat...........?.......................?....................365x5
    Deadlift........?.....................315x5...............435x5
    Weight........180...................192...................185
    BF%.............?......................12.....................12
    Time to Get Ripped
    Pictures of Me

  23. #23
    Wrecker of Homes d'Anconia's Avatar
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    Or maybe you could have set it up as the ratios of the two being equal to 1/2 and then try to solve for 't' or something I guess. If you could do that then it wouldn't be calculus.
    ...........||High School||.....||July '05||.......||January '09||
    Bench.........225x1...............275x1.................?
    Squat...........?.......................?....................365x5
    Deadlift........?.....................315x5...............435x5
    Weight........180...................192...................185
    BF%.............?......................12.....................12
    Time to Get Ripped
    Pictures of Me

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