COS in Google Sheets: Calculate Horizontal Components and Phase Offsets

• Introduced: original service launch date is not established by the official history reviewed; Sheets has no corresponding numbered desktop release in this guide.
• Availability: documented in the rolling Google Sheets service; examples use an ordinary web spreadsheet and numeric cells.
• Checked: October 14, 2026; official COS reference. Documentation and independent calculations, without native Sheets execution or broader client certification.

=COS(angle)

Google explicitly specifies radians. The input is an angle, and the result is dimensionless. If a cell already holds radians, use it directly rather than converting it a second time.

The examples use English names and decimal-point numbers. PI supplies the conversion constant; this guide does not infer a native internal precision guarantee from its display. Reported numerical results below are mathematical expectations.

Enter degrees −60, 0, 60, 120, 240 in A2:A6. In B2 enter and fill down:

=COS(A2*PI()/180)

Expected results are approximately 0.5, 1, 0.5, −0.5, −0.5. Opposite 60-degree inputs share the same value because cosine is even. Two other angles can also share a cosine through periodicity and symmetry.

=COS(60) instead returns approximately −0.952412980 because the number is interpreted as radians. A display suffix such as a degree sign does not change the formula’s argument convention.

For a vector of magnitude 14 measured at 60 degrees counterclockwise from the positive horizontal axis:

=14*COS(60*PI()/180)

Expected component: 7. At 120 degrees, the same model gives −7, indicating a leftward component. Keep the sign when direction matters; ABS would answer only a magnitude question.

This is a specified coordinate model. If the input is instead a slope angle measured from vertical, confirm which side is adjacent before choosing the expression. SIN supplies the vertical component for the horizontal-axis convention.

A constructed response has baseline 12, amplitude 3 and degree offset 30. Enter phases 0, 60, 150, 240 in D2:D5 and use:

=12+3*COS((D2+30)*PI()/180)

Expected values are approximately 14.598076211, 12, 9, 12. Parentheses ensure both the source phase and offset are converted together. Converting only the offset while leaving D2 in degrees mixes units within one argument.

The offset changes where the curve reaches its features; the amplitude and baseline retain their distinct roles. Keep all three parameters visible when adapting the formula, and do not treat this assumed curve as evidence about an unexamined dataset.

=ACOS(COS(240*PI()/180))*180/PI()

Expected result: 120 degrees. ACOS returns its principal angle from zero through 180 degrees. It cannot know whether a cosine of −0.5 originally came from 120 or 240 degrees.

For a separate ordinary angle of 20 degrees, the identity =COS(20*PI()/180)^2+SIN(20*PI()/180)^2 is expected to be approximately 1. Use such an identity to check the intended mathematics, without claiming bit-for-bit equality in every stored calculation.

Check the angle unit, reference axis and placement of parentheses before changing the model. A near-zero component can be sensitive to display precision; keep the underlying value for subsequent calculations and apply any reporting round only at the intended stage.

The cited function help establishes the radian definition. It does not certify arbitrary text coercion, every imported file behavior or extreme-angle accuracy. Test the actual spreadsheet separately where those boundaries matter.

• Google COS help.
• Editorial testing standards.

Worked inputs are fictional and outputs independently calculated. Approximate values are rounded mathematical expectations, not captured native results. Imported types, extreme magnitudes and a complete error/coercion matrix remain outside the tests.