var x=16;
var n=2;
var negate = n % 2 == 1 && x < 0;
if(negate)
x = -x;
var possible = Math.pow(x, 1 / n);
n = Math.pow(possible, n);
if(Math.abs(x - n) < 1 && (x > 0 == n > 0))
var result= negate ? -possible : possible;
document.getElementById("demo").innerHTML =
"
" + result;
