Investment Studio > Expressions > Functions > Math & Trig > ACOS

float acos(float argument)

Returns the arccosine of the argument. The argument must be in the range [-1, 1].

The arccosine is the angle such that cos(angle) = argument. It's expressed in radians. Range: [0, PI].

To convert the result to degrees, multiply by 180 / PI or use the degrees conversion function.

Example

=acos(-0.5)

returns 2.0943951023932 = 2 * PI / 3 radians. You can verify that

=cos(2 * PI / 3)

is -0.5. To express the arccosine in degrees, you can use

=degrees(acos(-0.5))

to get the answer 120 degrees.

See also asin, atan, atan2, cos.