Returns the inverse trigonometric cosine (the arccosine) of a number. This function calculates the principal value.
This function returns the inverse trigonometric cosine of Number, that is the angle (in radians) whose cosine is Number. The angle returned is between 0 and PI, i.e. [0,π].
Number is the real number, or a reference to a cell containing that number, between -1 and +1, whose inverse trigonometric cosine value is to be calculated.
If the value of Number is outside this range, the function returns an invalid numeric value (#NUM!) error.
- To return the angle in degrees, use the DEGREES function.
- Alternatively multiply by 180/PI() to convert the result from radians to degrees.
The GIF below illustrates the function ACOS.
|=ACOS(-1)||Inverse trigonometric cosine of -1||3.14159265358979 (PI radians or π)|
|=ACOS(0.5)||Inverse trigonometric cosine of 0.5||1.0471975511966 (radians)|
|=DEGREES(ACOS(0.5))||Inverse trigonometric cosine of 0.5. Further, converting angle in radians to degrees.||60° (degrees)|
|=ACOS(-0.5)*180/PI()||Inverse trigonometric cosine of -0.5. Further, converting angle in radians to degrees by multiplying by 180/PI().||120° (degrees)|
|=ACOS(2)||Inverse trigonometric cosine of 2 will return an invalid numeric value (#NUM!) error because 2 is out of its domain.||#NUM!|
Related LibreOffice functions:
Equivalent Excel functions: