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Math Help - simple expotential calculation?

  1. #1
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    simple expotential calculation?

    I don't get how to solve an equation when e is in the equation. I know that e = 2.718

    Say for example,

    How do I solve 5000e^(-.24)?

    This is what I got:

    5000 x 2.718^(-.24) and then I got stuck. How to do solve when its to the power of a fraction? (i.e. 0.24)?

    The answer should be approx. 3933.14

    Thanks
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  2. #2
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    e^(i*pi)'s Avatar
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    Quote Originally Posted by fabxx View Post
    I don't get how to solve an equation when e is in the equation. I know that e = 2.718

    Say for example,

    How do I solve 5000e^(-.24)?

    This is what I got:

    5000 x 2.718^(-.24) and then I got stuck. How to do solve when its to the power of a fraction? (i.e. 0.24)?

    The answer should be approx. 3933.14

    Thanks
    Don't approximate, also nobody is expecting you to solve it mentally!

    Just put in 5000 \times e^{-0.24} into your calculator.

    Wolfram gives the correct answer: http://www.wolframalpha.com/input/?i=5000*e^%28-.24%29
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  3. #3
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    equation

    Hello,

    Are you allowed to use the calculator or do you want to compute it just by hand???
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  4. #4
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    I'm not allowed to use a calculator.

    Can you show me how do i compute it by hand?

    Thanks!
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  5. #5
    Senior Member AllanCuz's Avatar
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    Quote Originally Posted by fabxx View Post
    I'm not allowed to use a calculator.

    Can you show me how do i compute it by hand?

    Thanks!
    That task most certainly is not possible. You can simplify it a little bit...but that's about it

    5000 * 2.718^{-.24}

    \frac{ 5000 }{2.718^{.24} }

    \frac{ 5000 }{2.718^{.24 + .01 - .01} }

    \frac{ 5000 }{2.718^{\frac{1}{4}} 2.718^{-.01} }

    \frac{ 5000 * 2.718^{.01} }{2.718^{\frac{1}{4}}}

    How on god's green earth you're expected to calculate this by hand I do not know
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  6. #6
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    So, are you saying that you can't calculate e by hand?

    How about e^(0.07)? Thanks

    What about for example:

    5^(0.07). How do you calculate this by hand?

    Much appreciated
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  7. #7
    Senior Member AllanCuz's Avatar
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    Quote Originally Posted by fabxx View Post
    So, are you saying that you can't calculate e by hand?

    How about e^(0.07)? Thanks

    What about for example:

    5^(0.07). How do you calculate this by hand?

    Much appreciated
    It's not possible to compute that by hand. Let's look at an example,

     10^{ \frac{1}{4} }

    This will equal whatever number multiplied by 4 times yields 10. In this case, the answer is hard to do by hand and we have a nice fraction. Nevermind having .07 as the exponent.
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  8. #8
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    Ah, i see!

    Thank you!
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  9. #9
    MHF Contributor Bruno J.'s Avatar
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    You are probably just expected to leave the answer in a logarithm form.
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