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Please help me with my precal homework

  1. Oct 4, 2005 #1


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    okay here's the equation:
    In a certain molecular structure, the total energy E between two ions is given by

    E= (-5.6/r) + 10e^(-r/3)
    where r is the distance seperating the nuclei.

    now i already sketched the graph but i don't know how to find the domain of E, or find values of r that make sense in the problem situation, or find the realative maximum or minimum values or the total potential energy on the interval (0, ∞) . the y in that interval is supposed to be infinite in case you can't tell what it is.

    i tried to just look on the table but y never equals zero on there so im lost. then i tried to just stick in zero for y on the equation. i got stuck .
    Last edited: Oct 4, 2005
  2. jcsd
  3. Oct 5, 2005 #2


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    Gold Member

    you gave the equation, but whats the question that goes with it?
  4. Oct 5, 2005 #3


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    Science Advisor

    Do you know what "domain" means. And, as kreil asked, what was the question?
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