Square root
B = sqrt( returns
the square root of each element of the array X)X.
For the elements of X that are negative or complex, sqrt(X) produces
complex results.
The sqrt function’s domain includes
negative and complex numbers, which can lead to unexpected results
if used unintentionally. For negative and complex numbers z
= u + i*w, the complex square root sqrt(z) returns
sqrt(r)*(cos(phi/2) + 1i*sin(phi/2))
where r = abs(z) is the radius and phi
= angle(z) is the phase angle on the closed interval -pi
<= phi <= pi.
If you want negative and complex numbers to return error messages
rather than return complex results, use realsqrt instead.
See sqrtm for the matrix square
root.