COS Function (OpenOffice Calc)

Math Beginner OpenOffice Calc Introduced in OpenOffice.org 3.0
trigonometry cosine radians periodic math

The COS function in OpenOffice Calc returns the cosine of an angle (in radians). Learn syntax, degree conversion, examples, and best practices.

Compatibility

What the COS Function Does

  • Computes the cosine of an angle
  • Angle must be in radians
  • Useful for geometry, waves, oscillations, and rotations
  • Works across sheets
  • Pairs naturally with SIN, TAN, and PI

COS is ideal when you need horizontal components or phase‑shifted waveforms.

Syntax

COS(number)

Arguments:

  • number — Angle in radians
If your angle is in degrees, convert it using:
Degrees * PI() / 180

Basic Examples

Cosine of an angle in radians

=COS(PI())

Result: -1

Cosine of 60 degrees

=COS(60 * PI() / 180)

Result: 0.5

Cosine using a cell reference

=COS(A1)

(Assumes A1 is in radians.)

Convert degrees to radians inside COS

=COS(RADIANS(A1))

Advanced Examples

Cosine wave function

=COS(2 * PI() * Frequency * Time)

Phase‑shifted sine wave (90° shift)

=COS(2 * PI() * f * t)

Equivalent to:

=SIN(2 * PI() * f * t + PI()/2)

Damped cosine wave

=EXP(-Decay * Time) * COS(2 * PI() * Frequency * Time)

Polar to Cartesian conversion

X:

=Radius * COS(AngleRadians)

Y:

=Radius * SIN(AngleRadians)

Oscillation model

=Amplitude * COS(2 * PI() * t / Period)

COS across sheets

=COS(Sheet1.A1)

COS in array formulas

=COS(A1:A10)

Confirm with Ctrl+Shift+Enter.

Cosine of a sum (wave interference)

=COS(A1 + A2)

Rotating a point by θ

New X:

=X0 * COS(θ) - Y0 * SIN(θ)

New Y:

=X0 * SIN(θ) + Y0 * COS(θ)

Common Errors and Fixes

COS returns unexpected values

Almost always caused by:

  • Using degrees instead of radians
  • Forgetting to convert: Degrees * PI() / 180
  • Incorrect parentheses

COS returns Err:502 (Invalid argument)

Occurs when:

  • Input is text
  • Input is empty
  • A malformed reference is used

COS ignores values you expected it to include

COS ignores:

  • Text numbers ("123")
  • Empty cells
  • Logical values
  • Errors

COS includes values you expected it to ignore

COS includes:

  • Dates
  • Times
  • Numeric results of formulas

Err:508 — Missing parenthesis

Usually caused by:

  • Missing )
  • Using commas instead of semicolons

Best Practices

  • Always convert degrees to radians
  • Use COS for horizontal components and phase‑shifted waves
  • Use named ranges for angles and frequencies
  • Keep parentheses clean in multi‑step trig formulas
  • Pair COS with SIN for coordinate transformations
COS is just SIN shifted by 90° — use that relationship to simplify wave and rotation formulas.

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