Function coth

pub fn coth(radians: FLOAT) -> FLOAT

Returns the hyperbolic cotangent of the argument given in radians

assert_approx_eq(coth(1.0), cosh(1.0)/sinh(1.0), 1e-10);

assert_approx_eq(coth(0.5), cosh(0.5)/sinh(0.5), 1e-10);

assert_approx_eq(coth(0.1), cosh(0.1)/sinh(0.1), 1e-10);