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This is documentation for Caché & Ensemble. See the InterSystems IRIS version of this content.

For information on migrating to InterSystems IRIS, see Why Migrate to InterSystems IRIS?


Returns the arc-cosine of an angle.




number An expression that resolves to a number in the range -1 to 1 (inclusive). Values outside of this range generate an <ILLEGAL VALUE> error.


The ACOS function returns the trigonometric arc-cosine of number. An arc-cosine is the inverse of a cosine.

By default, Caché MVBasic trig functions return results in degrees. To return results in radians, set $OPTIONS RADIANS.

To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.


The following example uses the ACOS function to return the arc-cosine of an angle:

PRINT ACOS(-0.5):" in degrees"
PRINT ACOS(-0.5)*(3.1415/180)):" in radians"

See Also