Function sqrt 

pub fn sqrt(x: f64) -> f64

Returns the square root of x, where x is a non-negative number.

sqrt(9)     # Returns 3
sqrt(10.24) # Returns 3.2
sqrt(-1)    # Returns NaN

Note: Negative values of x return NaN (“Not a Number”). In C#, if you need negative inputs, use System.Numerics.Complex.