ACOS

Description: Returns the arccosine, or inverse cosine, of a number. The arccosine is the angle whose cosine is Number. The returned angle is given in radians in the range 0 (zero) to pi.

Syntax: ACOS(Number)

• Number is the cosine of the angle you want and must be from -1 to 1.

Remarks:

• If you want to convert the result from radians to degrees, multiply it by 180/PI or use the DEGREES function.

• When used in an event analysis flowchart, Number must evaluate to a numerical value. It can include:

• Numerical values

• Standard operands (+, -, *, /)

• Predefined mathematical functions (exp, log, sin, etc.)

• Event analysis internal functions

• Event analysis resources

• References to any ReliaSoft Workbooks

Example:

• ACOS(-0.5) = 2.094395 [the arccosine of -0.5 in radians]

• ACOS(-0.5)*180/PI() = 120 [the arccosine of -0.5 in degrees]

• DEGREES(ACOS(-0.5)) = 120 [the arccosine of -0.5 in degrees]