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IMCONJUGATE

Supported, behaves as documented

Category: Engineering · Last tested 2026-09-01

Real compatibility results for the IMCONJUGATE function: executed in Excel for the web, Google Sheets and LibreOffice Calc, with desktop Excel behavior from Microsoft’s official documentation (we do not run desktop Excel — Excel for the web is a different application and is executed separately). Syntax and links to that documentation are below.

Support matrix

EngineDocumentedLive-testedVerdict
Excel (desktop)Yes No — documented only n/a
Excel for the web— Yes (recalc, 2026-09-01) Supported, behaves as documented
Google SheetsYes Yes (Drive import, 2026-08-31) Supported, behaves as documented
LibreOffice CalcYes Yes (25.8.7.3, 2026-08-31) Supported, behaves as documented

LibreOffice version history

We executed the same test cases under each LibreOffice release to show exactly when IMCONJUGATE’s support changed — not documentation claims, real results.

LibreOffice versionVerdictTested
24.2.0.3 Supported, behaves as documented 2026-08-31
24.8.7.2 Supported, behaves as documented 2026-08-31
25.2.0.3 Supported, behaves as documented 2026-08-31
25.8.7.3 Supported, behaves as documented 2026-08-31

Executed test cases

Excel for the web (executed 2026-09-01 via OneDrive recalculation)

These values come from Excel for the web, not from desktop Excel. They are two different implementations of the calculation engine, and this run measured only the web one: the corpus was uploaded to OneDrive as .xlsx, recalculated by Excel for the web on open, and downloaded again for readback. Excel for the web is a rolling service with no pinnable version, so the run is identified by its date. Where a value here disagrees with the Expected column — which is Microsoft’s documentation of the desktop product — we cannot tell you whether the web engine diverges from the desktop one or the documentation is wrong about both, because we do not run desktop Excel.

FormulaDescriptionResultExpectedVerdict
=IMCONJUGATE("3+4i") Microsoft's documented worked example: the complex conjugate of 3+4i 3-4i 3-4i
Provenance

Microsoft publishes '=IMCONJUGATE("3+4i")' with the result 3-4i, a string. Derived from the definition: the conjugate negates the imaginary part and leaves the real part alone. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("3-4j") A j-suffixed input, whose suffix must survive into the result 3+4j 3+4j
Provenance

Microsoft documents every IM* function as accepting "a complex number in x + yi or x + yj text format", so the j suffix is not an alternative spelling this corpus invented -- it is half of the documented input grammar, and an engine that parses only the i form is incompatible on documented input. The suffix is a property of the value's notation, not of the function, so an engine that accepts j on input but emits i on output has silently rewritten the user's notation -- which is why this is asserted as a string rather than checked numerically. The conjugate of 3-4j is 3+4j. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("5") A real number is its own conjugate, and must come back with no imaginary part at all 5 5
Provenance

Derived from the definition (negating a zero imaginary part changes nothing) plus the documented output format. The interesting half is the FORMATTING: the result must be the bare "5", not "5+0i" or "5-0i". EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched

Google Sheets (executed 2026-08-31 via Drive import)

Google Sheets is a rolling service with no pinnable version, so this run is identified by its date. The corpus was imported to Drive as .xlsx, recalculated by Sheets, and exported back for readback.

FormulaDescriptionResultExpectedVerdict
=IMCONJUGATE("3+4i") Microsoft's documented worked example: the complex conjugate of 3+4i 3-4i 3-4i
Provenance

Microsoft publishes '=IMCONJUGATE("3+4i")' with the result 3-4i, a string. Derived from the definition: the conjugate negates the imaginary part and leaves the real part alone. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("3-4j") A j-suffixed input, whose suffix must survive into the result 3+4j 3+4j
Provenance

Microsoft documents every IM* function as accepting "a complex number in x + yi or x + yj text format", so the j suffix is not an alternative spelling this corpus invented -- it is half of the documented input grammar, and an engine that parses only the i form is incompatible on documented input. The suffix is a property of the value's notation, not of the function, so an engine that accepts j on input but emits i on output has silently rewritten the user's notation -- which is why this is asserted as a string rather than checked numerically. The conjugate of 3-4j is 3+4j. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("5") A real number is its own conjugate, and must come back with no imaginary part at all 5 5
Provenance

Derived from the definition (negating a zero imaginary part changes nothing) plus the documented output format. The interesting half is the FORMATTING: the result must be the bare "5", not "5+0i" or "5-0i". EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched

LibreOffice Calc 25.8.7.3 (tested 2026-08-31)

FormulaDescriptionResultExpectedVerdict
=IMCONJUGATE("3+4i") Microsoft's documented worked example: the complex conjugate of 3+4i 3-4i 3-4i
Provenance

Microsoft publishes '=IMCONJUGATE("3+4i")' with the result 3-4i, a string. Derived from the definition: the conjugate negates the imaginary part and leaves the real part alone. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("3-4j") A j-suffixed input, whose suffix must survive into the result 3+4j 3+4j
Provenance

Microsoft documents every IM* function as accepting "a complex number in x + yi or x + yj text format", so the j suffix is not an alternative spelling this corpus invented -- it is half of the documented input grammar, and an engine that parses only the i form is incompatible on documented input. The suffix is a property of the value's notation, not of the function, so an engine that accepts j on input but emits i on output has silently rewritten the user's notation -- which is why this is asserted as a string rather than checked numerically. The conjugate of 3-4j is 3+4j. EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched
=IMCONJUGATE("5") A real number is its own conjugate, and must come back with no imaginary part at all 5 5
Provenance

Derived from the definition (negating a zero imaginary part changes nothing) plus the documented output format. The interesting half is the FORMATTING: the result must be the bare "5", not "5+0i" or "5-0i". EXCEL'S COMPLEX-STRING FORMAT, which this corpus derives rather than assumes: a result is rendered as the real part, then the sign, then the imaginary coefficient followed by the suffix, with each part printed to at most 15 significant digits and trailing zeros stripped; a zero real part is omitted entirely, a zero imaginary part reduces the result to a bare real number, and an imaginary coefficient of exactly 1 or -1 prints as "i" / "-i" with no digit. That rule was not taken on faith -- it was written as a formatter in Python and validated against SEVEN independently published Microsoft strings in this batch alone (IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP and IMLN), which it reproduces byte for byte, before being used to predict any value this corpus asserts. String results are compared exactly, so a formatting-only difference (a trailing zero, "1i" for "i", a different digit count) fails the case and is recorded as its own divergence class, separate from a wrong numeric value.

Matched

Docs & syntax