Return the non-negative square root of Float {expr} as a |Float|. {expr} must evaluate to a |Float| or a |Number|. When {expr} is negative the result is NaN (Not a Number). Examples: :echo sqrt(100) 10.0 :echo sqrt(-4.01) nan "nan" may be different, it depends on system libraries. Can also be used as a |method|: Compute()->sqrt() {only available when compiled with the |+float| feature}