MDETERM in Collabora Office: Calculate Determinants and Check Matrix Structure

• 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. Function-specific documentation and independently derived controls; no native Collabora test was performed.

=MDETERM(Array)

The direct Collabora reference requires a square input array. It explicitly says the determinant returns in the current cell; no multi-cell result range is required. The array-function overview also lists MDETERM among functions that handle area references as arrays.

All examples use numeric cells, English function names and the documented desktop-help scope. The calculations are independent mathematical controls, not native application observations.

Enter this input in A2:B3, with no headings inside that range:

Place the formula outside A2:B3:

=MDETERM(A2:B3)
=A2*B3-B2*A3

Both expected results are 10. The explicit expression is a two-by-two determinant check, not a general algorithm for larger matrices. A sum of all four entries also happens to be 10 here, so use the next controls to show that simple addition is not the operation being performed.

On a separate sheet, reverse the row order to (2,3) followed by (4,1). The determinant is −10, while the sum of entries is still 10. Swapping two rows reverses the determinant’s sign.

The magnitude can describe an area scale, but the sign carries orientation information. A negative determinant is not itself an input error or proof that a matrix cannot be inverted.

Use these separate two-by-two controls:

The first doubles only the original first row and doubles the determinant. The second doubles both rows, so the determinant is multiplied by four. For a two-by-two matrix, scaling every entry by c scales the determinant by c².

This distinction is useful when checking unit conversions. It is a mathematical property of the explicit matrices, not evidence that every floating-point input will satisfy an exact equality in native software.

Enter this matrix in D2:F4 on another part of the sheet:

=MDETERM(D2:F4)

Expected result: 36, the product 2×3×6 of the diagonal entries. That shortcut works for a triangular matrix, where all entries on one side of the diagonal are zero. It does not authorize multiplying just the diagonal of an arbitrary matrix.

The matrix with rows (4,1) and (8,2) has determinant 0 because its second row is twice its first. It has no inverse in ordinary matrix algebra. See MINVERSE for the separate inverse operation.

A different matrix, with rows (1,1) and (1,1.000001), has mathematical determinant 0.000001. The rows are almost dependent. This example demonstrates sensitivity; the exact stored decimal, native output precision and error threshold have not been tested. Do not classify all small nonzero determinants as zero using a universal hard-coded cutoff.

Using the original matrix’s columns as two planar vectors gives a parallelogram area of 10 and triangle area 5. This is an interpretation of those coordinates; unrelated data columns need not represent geometry.

The cited Collabora section does not enumerate exact errors for nonsquare, text, blank or error-containing inputs. This guide therefore requires a square all-numeric fixture and leaves those native cases unverified. It also makes no universal maximum-size or numerical-accuracy claim. MMULT multiplies matrices, while MUNIT constructs an identity matrix for further checks.

• Collabora Office 26.04: MDETERM and array entry.
• Editorial testing standards.

Complete matrices and outputs were independently calculated using arithmetic and exact rational checks where appropriate. They are documentation-backed expectations, not native Collabora captures or a certification of every type, error and client boundary.