Other than the snarky RTFM (Perl has an intrinsic exponentiation operator)

$x = $y ** (1/4) if $y > 0;

[download]
 This is the revised code, in response to salva's and ikegami's comments 
if($y >= 0){
    $x = $y ** (1/4);
}else{
    undef($x);
    die "Even roots of negative numbers require complex arithmetic\n";
}

[download]

While the 4th root of a negative number exists, I'm presuming you don't need to do complex arithmetic. If you do, you man want to check out Math::Complex, although it appears to be developmental.

emc

"Being forced to write comments actually improves code, because it is easier to fix a crock than to explain it. "
—G. Steele

In reply to Re: Calculating Nth root using perl. by swampyankee
in thread Calculating Nth root using perl. by Anonymous Monk

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