CSC Function (Gnumeric)

CSC calculates an angle’s cosecant, the reciprocal of its sine. For example, the mathematically expected result of =CSC(RADIANS(30)) is 2. Gnumeric’s official manual says the argument x is an angle in radians; entering CSC(30) instead treats 30 as radians, not 30 degrees. Gnumeric CSC.

=CSC(x)

CSC(x)=1/SIN(x) when SIN(x)≠0. The input is numeric; no default or optional argument is described. Gnumeric’s manual marks CSC OpenFormula compatible, while its Microsoft Excel compatibility sentence states not Excel compatible. That last statement must be interpreted in documentation/version context because modern Excel does document CSC. Gnumeric catalogue classifies this function as Unique to Gnumeric / No Testsuite; this catalogue label is not a test result and should not be treated as a modern Excel support matrix. Manual · Catalogue · Microsoft CSC.

Type the degree inputs in A2:A7. Enter =CSC(RADIANS(A2)) in B2 and fill down, or enter the listed formula for each row. The RADIANS wrapper turns the human-entered angle into the units CSC expects.

The expected values were calculated independently using Python 1/sin(radians(degrees)); simple-angle identities provide a second check: CSC(π/6)=2, CSC(π/4)=√2, CSC(π/2)=1, and CSC(3π/2)=−1. This is independent calculation, not native Gnumeric observation.

A useful comparison

In C2, try the proposed formula =1/SIN(RADIANS(A2)) and fill down. For angles whose sine is sufficiently far from zero, the expected C results are nearly equal to the expected B results. Comparing within a tolerance is better than exact equality because floating-point implementations may differ.

In a right triangle, sin(angle) = opposite/hypotenuse. Therefore hypotenuse = opposite * CSC(angle) for a valid angle with positive sine. Consider a synthetic brace rising 2 metres above a horizontal surface at 30°.

Expected result: C10 = 4 metres, independently checked because sin(30°)=0.5. This calculation is a teaching model, not a structural design recommendation. Check that the angle is strictly between 0° and 180° and has physically meaningful orientation before applying it to real measurements.

For a small positive-angle workflow an illustrative guard is:

=IF(ABS(SIN(RADIANS(A10)))<0.000001,"Angle too close to singularity",B10*CSC(RADIANS(A10)))

Not a universal safeguard: the 0.000001 threshold is an illustrative tolerance selected for this example, not an official Gnumeric limit. Native behavior, display formatting and local comma/decimal conventions still require testing.

• Zeros of sine: mathematically CSC(k*π) is undefined for integer k; near such angles, tiny input/rounding changes cause huge outputs. Do not claim that CSC(PI()) must display a particular error or infinity, since floating-point PI()/SIN() may not be exactly zero.
• Degrees versus radians: =CSC(30) is a radian input, not the 30° example above. Use RADIANS when data are in degrees.
• Angle format: formatting a number as degrees does not necessarily change its underlying unit. Confirm cell values and formula.
• Nonnumeric cells/empty strings: the manual provides a type description but not a full coercion/error table; exact Gnumeric error codes need native execution.
• Version/build support: official catalogue presence is not proof that all installations or historic versions support the same inputs and outcomes.

The Gnumeric manual calls CSC OpenFormula-compatible and states it is not Excel compatible; the current Microsoft reference independently documents CSC(number) in recent Excel versions. These facts can coexist because compatibility labels and product capabilities change over time. Do not carry Microsoft’s Excel-specific magnitude constraints, coercion or error codes into Gnumeric claims, and test any workbook interchange in both apps. Gnumeric CSC · Microsoft CSC documentation.

SIN, RADIANS, DEGREES, SEC, COT.

The official Gnumeric reference establishes the function’s purpose and argument structure. The arguments and worked examples were editorially reviewed and the stated expected results were independently calculated.

Review date: 2026-10-12. No native application run: the worked outputs are documentation-based or independently calculated expectations, not measurements from installed Gnumeric. Ordinary numeric cases and the stated text-construction examples are checked; blank/text coercion, machine extremes and workbook round trips are not certified. The formula editor in your installed version is the authority for localized separators.

Example-check record · Editorial standards.