Find only the rational zeros. x^4 + 9

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- Mar 19th 2006, 08:14 PMkharris82Rational Zero's problem
Find only the rational zeros. x^4 + 9

Thanks! - Mar 19th 2006, 11:44 PMCaptainBlackQuote:

Originally Posted by**kharris82**

$\displaystyle

x^4+9=0

$

This may be rewritten as:

$\displaystyle

x^4=-9

$.

Now as $\displaystyle x$ is real $\displaystyle x^4$ is positive which contradicts

the equation, so there can be no real roots of $\displaystyle x^4+9=0$, and

so there are no rational roots.

RonL