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Math Help - Need to find value for X

  1. #1
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    Need to find value for X



    Can some one please let me know how the value for x is 2.13?

    Thanks a lot.
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  2. #2
    MHF Contributor Siron's Avatar
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    Re: Need to find value for X

    What have you tried? Have you learned to solve equations yet?
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  3. #3
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    Re: Need to find value for X

    Quote Originally Posted by Siron View Post
    What have you tried? Have you learned to solve equations yet?
    No I have not
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    Re: Need to find value for X

    Quote Originally Posted by thashrif View Post


    Can some one please let me know how the value for x is 2.13?

    Thanks a lot.
    Before I can proceed, I need to know if you meant to type (1 + x^2)/12 or
    1 + (x^2/12) for the numerator part of the fraction.
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  5. #5
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    Re: Need to find value for X

    Quote Originally Posted by mathland View Post
    Before I can proceed, I need to know if you meant to type (1 + x^2)/12 or
    1 + (x^2/12) for the numerator part of the fraction.
    Hi, Thank you very much for looking into this, the numerator part should be (1 + x^2)/12

    Thanks a lot
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  6. #6
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    Re: Need to find value for X

    So the problem is to solve 1.6911= 1.6242\frac{\frac{1+ x^2}{12}}{1.0062}.

    First do the arithmetic on the right:  \frac{1.6242}{12(1.0062)}= 0.134516 to 6 decimal places. That means the equation is 1.611= 0.134516(1+ x^2). Divide both sides by 0.134516: 0.134516= x^2+ 1.

    Subtract 1 from both sides. x^2= -0.8655 which has no real number soltutions. if you are allowed complex numbers, the solution is plus or minus \sqrt{0.8655} times i.
    Last edited by CaptainBlack; November 29th 2011 at 08:15 PM. Reason: fix LaTeX
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  7. #7
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    Re: Need to find value for X

    Quote Originally Posted by thashrif View Post


    Can some one please let me know how the value for x is 2.13?

    Thanks a lot.
    I worked this problem twice and did not come close to your answer for x.

    You say that x = 2.13.

    If x = 2.13, then after evaluation, we should get the same answer on both sides of the equation.

    Let x = 2.13

    1.6199 = 1.6242 [(1 + x^2)/12)] divided by 1.0062

    1.6199 = 1.6242 [(1 + (2.13)^2)/12)] divided by 1.0062

    1.6199 = 1.6242 [(1 + 4.5369)/12)] divided by 1.0062

    1.6199 = 1.6242 [(5.5369)/12)] divided by 1.0062

    As I continued to simplify, I did not get 1.6199 on both sides of the equation. So, the answer for x that you suggested (2.13) is not correct.
    Find a calculator and continue simplifying where I ended my computation. I'm sure you will agree.
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  8. #8
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    Re: Need to find value for X

    Quote Originally Posted by thashrif View Post
    No I have not
    the equality is true.
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  9. #9
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    Re: Need to find value for X

    Quote Originally Posted by HallsofIvy View Post
    That means the equation is 1.611= 0.134516(1+ x^2). Divide both sides by 0.134516: 0.134516= x^2+ 1.
    Mistake?

    First it should be 1.6911 instead of 1.611.

    Secondly,

    \frac{1.611}{0.134516}= 11.98 (2 d.p.)

    Correct me if I am wrong.

    Quote Originally Posted by thashrif View Post
    Hi, Thank you very much for looking into this, the numerator part should be (1 + x^2)/12

    Thanks a lot
    http://www.wolframalpha.com/input/?i=1.6199+%3D+1.6242*%28%281+%2B+x^2%29%2F%2812*1. 0062%29%29+find+x
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