## Finding unknown n th roots ?

Complex numbers, rational functions, logarithms, sequences and series, matrix operations, etc.
wp_913
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Joined: Mon May 16, 2011 12:01 am
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### Finding unknown n th roots ?

HI

I'm having trouble finding a solution to a fractional exponent that has an unknown denominator

such as 0.20 = 28.6 x (1/2)^3/x

I can easily determine the solution when the numerator of the fractional exponent is the unknown, but I'm stumped as how to determine the unknown value for a fractional exponent's denominator?

Any references would be most helpful

stapel_eliz
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Joined: Mon Dec 08, 2008 4:22 pm
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I'm having trouble finding a solution to a fractional exponent that has an unknown denominator

such as 0.20 = 28.6 x (1/2)^3/x
Is the first "x" a variable or a "times" sign?

Formatting Math as Text

wp_913
Posts: 5
Joined: Mon May 16, 2011 12:01 am
Contact:

### Re: Finding unknown n th roots ?

Hi All,

Ok I found the answer to my question by having it right in front of me and not realizing it.

I just take the log of both sides of the equation, isolate the variable by division, which leaves me with 7.1584 = x/0.4191.Then I just solve for x.

It took me a while to realize that it does not matter if the fractional exponent has a variable in the numerator or denominator.

Hopefully this may help someone else.