To calculate a root square in python, there are several options:

#### Positive float

`>>> x = 9.0`

`>>> x**(0.5)`

`3.0`

with pow() function:

`>>> pow(x,0.5)`

`3.0`

with math module

`>>> import math`

`>>> math.sqrt(x)`

`3.0`

with numpy

`>>> import numpy as np`

`>>> np.sqrt(x)`

`3.0`

#### Complex number

`>>> z = 1j`

`>>> z`

`1j`

with numpy

`>>> import numpy as np`

`>>> np.sqrt(z)`

`(0.7071067811865476+0.7071067811865475j)`

with pow():

`>>> pow(z,0.5)`

`(0.7071067811865476+0.7071067811865475j)`

#### Matrix

`>>> import numpy as np`

`>>> a = np.array((16,9,4,25))`

`>>> np.sqrt(a)`

`array([4., 3., 2., 5.])`

### References

Links | Site |
---|---|

Racine carrée | wikipedia |

Which is faster in Python: x**.5 or math.sqrt(x)? | stackoverflow |

How do I calculate square root in Python? | stackoverflow |

Root mean square of a function in python | stackoverflow |

Complex numbers usage in python | stackoverflow |

Nombres complexes RACINES | villemin.gerard.free.fr |