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excelalgebra

Simplifying an equation with negative exponents


It has been 15 years since I needed to do any complicated algebraic equation simplification. Specifically, I need to simplify this equation so that it will properly calculate in an Excel spreadsheet. I'm doing nonlinear optimization models so sometimes x=0 resulting in an error. I know to flip the numerator & denominator to get rid of the negative. However, I'm still getting a Div/0 error. If someone could just give me the properly simplified version, I will be able to back into what you did to understand how to apply it in the future.

(35 + 100x^-(1/3))*x

EDIT, I forgot one piece of the formula, everything inside the () is * x too. Update it.


Solution

  • Sadly you cannot avoid the laws of simple maths. This formula:

    =35+B1^(-1/3)
    

    is equivalent to:

    =35+1/B1^(1/3)
    

    if you set B1 to zero we get the equivalent to:

    =35 + 1/0
    

    which will raise the error.

    EDIT#1:

    (35 + 100x^-(1/3))*x
    

    is the same as:

    35*x + 100 * x^(-1/3) * x^1
    

    is the same as:

    35*x + 100 * x^(2/3)
    

    and if we set x=0 we get

    35*0 + 100*0
    

    which is:

    0