description:
sqrt ket
square root the coefficients
return x^(1/2)
examples:
sqrt (9|x> + 25|y> + 49|z>)
3|x> + 5|y> + 7|z>
sqrt square (0.2|x> + 3|y> - 5|z>)
0.2|x> + 3|y> + 5|z>
see also:
square, abs