ACOS

ACOS(number)

Returns the arc-cosine of a number.

number

The number you want the arc-cosine of.

REMARKS

* For an illustrated example refer to the Trigonometric Functions page.
* The inverse of this function is the COS function.
* This function is also called the inverse cosine function.
* The "number" is the cosine of an angle in radians.
* If "number" is not numeric, then #VALUE! is returned.
* The angle returned is in radians between 0 and PI.
* If your argument is in degrees, multiply it by PI/180 to convert it to radians.
* If your argument is in radians, multiply it by 180/PI to convert it to degrees.
* If you want to convert the result from radians to degrees, multiply it by 180/PI.
* You can use the COS function to return the cosine.
* You can use the ACOT function to return the the arc-cotangent.
* You can use the ASIN function to return the arc-sine.
* You can use the ATAN function to return the arc-tangent.
* You can use the DEGREES function to convert from radians to degrees.
* For the Microsoft documentation refer to support.microsoft.com
* For the Google documentation refer to support.google.com

	A
1	=ACOS(0.5) = 1.047
2	=ACOS(-1) = 3.142
3	=ACOS(1) = 0
4	=ACOS(COS(1)) = 1
5	=ACOS(COS(0.5)) = 0.5
6	=ACOS(-0.5)*180/PI() = 120
7	=ACOS(-1)*180/PI() = 180
8	=DEGREES(ACOS(-1)) = 180
9	=ACOS(DEGREES(-0.5)*PI()/180), 180/PI() = 120
10	=ACOS(10) = #NUM!
11	=ACOS("some text") = #VALUE!

1 - What is the arc-cosine of 0.5 radians.
2 - What is the arc-cosine of -1 radians.
3 - What is the arc-cosine of 1 radian.
4 - This function is the inverse of the cosine function.
5 - This function is the inverse of the cosine function.
6 - How many degrees is the arc-cosine of -0.5 radians.
7 - How many degress is the arc-cosine of -1 radians.