Function coth

src/compute-engine/interval/trigonometric.ts:498–506

(x: Interval | IntervalResult)

}

/**
 * Hyperbolic cotangent: coth(x) = cosh(x)/sinh(x).
 *
 * Has a singularity at x = 0.
 */
export function coth(x: Interval | IntervalResult): IntervalResult {
  const unwrapped = unwrapOrPropagate(x);
  if (!Array.isArray(unwrapped)) return unwrapped;
  const [xVal] = unwrapped;
  if (containsZero(xVal)) {
    return { kind: 'singular', at: 0 };
  }