pub fn root_two_pi<T: RealNumber>() -> T
Returns the square root of 2pi.
four_over_pi()
half_pi()
one_over_pi()
one_over_two_pi()
pi()
quarter_pi()
root_half_pi()
root_pi()
three_over_two_pi()
two_over_pi()
two_over_root_pi()
two_pi()