ACOSH in Collabora Office: Recover a Nonnegative Hyperbolic Argument

• Introduced: original Collabora release and launch date are not established by the sources reviewed.
• Availability: documented in Collabora Office 26.04 help, scoped to the desktop-help release.
• Platform scope: support in every online or mobile deployment is not inferred from desktop documentation.
• Checked: October 14, 2026. Direct function-specific documentation and independent numerical examples; no native Collabora test was performed.

=ACOSH(number)

Collabora’s reference requires number>=1. The result is the hyperbolic argument whose COSH equals the input, using the nonnegative branch.

This is not an angle conversion. ACOSH is paired with COSH, while the inverse of circular cosine is ACOS. The circular and hyperbolic functions have different domains and output interpretations.

The formulas use English names and semicolon separators where required. Numerical results below are independently calculated expectations rounded for readability.

Enter 1, 1.5, 2, 5 in A2:A5. In B2 enter and fill down:

=ACOSH(A2)

Expected B2:B5, approximately: 0, 0.962423650, 1.316957897, 2.292431670. The smallest allowed real input produces zero. Larger inputs produce positive results.

Do not extend this table to 0.5 and expect a real output. The domain requirement is part of the function’s meaning, not a formatting inconvenience. This guide does not assign an exact product error code to every invalid input without a native test.

=COSH(ACOSH(2))
=COSH(ACOSH(5))

Expected results, within numerical precision: 2 and 5. These controls check that the inverse result maps back to the supplied hyperbolic cosine value.

Round-trip equality should use an appropriate numerical tolerance in a larger model. Display rounding can make two stored values appear identical even when their final digits differ.

Compare:

=ACOSH(COSH(2))
=ACOSH(COSH(-2))

Expected result for both: approximately 2. COSH is even, so COSH(2) and COSH(−2) are the same. ACOSH cannot recover which sign was originally used; its real branch is nonnegative.

For inputs −2, −1, 0, 1, 2, applying ACOSH(COSH(input)) yields approximately 2, 1, 0, 1, 2. If a signed original parameter matters, retain that sign separately rather than expecting the inverse to recreate information that COSH discarded.

Suppose an illustrative relationship is y=3*COSH(x) and the observed model value is 6. To recover the nonnegative x:

=ACOSH(6/3)

Expected result: approximately 1.316957897. Substitution into =3*COSH(ACOSH(6/3)) reconstructs approximately 6.

The model requires y/3≥1, so its real-valued outputs satisfy y≥3. A supplied y of 2 would contradict that model’s real domain. Do not silently clip it to 3 unless a separate measurement policy explicitly allows that transformation.

This is a constructed algebraic example, not a fitted description of any actual process. The coefficient and domain should come from the task’s specification.

=ACOSH(1.0001)

Expected result: approximately 0.014142018. A small change from the boundary value 1 produces a nonzero inverse result. Near a domain boundary, input precision can matter more than the displayed number of decimal places suggests.

Keep raw inputs available. A cell formatted to show 1.0000 might contain a value slightly above or below 1. The displayed text alone does not establish whether the underlying number belongs to the real domain.

For moderate valid inputs, ACOSH can be expressed as:

=LN(A2+SQRT(A2^2-1))

At A2=2 the expression is approximately 1.316957897. It connects the inverse to LN and SQRT, but it is not a recommendation to replace the dedicated function in every numerical situation.

The squared term can become too large for finite numerical representation, and subtraction near 1 can affect precision. Native extreme-input behavior and all error/coercion cases remain outside this article’s tests.

Verify the input is a numeric hyperbolic cosine value, that any scale factor was removed correctly and that the value is at least 1. Confirm whether a nonnegative result is sufficient for the model. If a negative original argument must be recovered, extra information is required.

Keep a boundary control at 1, a moderate valid value such as 2 and an explicitly rejected out-of-domain example in your review notes. Those checks are more informative than comparing only one convenient forward/inverse pair.

• Collabora Office 26.04: ACOSH.
• Editorial testing standards.

The official section supplies the product-specific definition and documented domain or angle branch. Original worked values were independently calculated. Native execution, extreme-value benchmarks and broader client compatibility remain unverified.