• This function returns the arc cosine of the given number or expression.
  • The result is expressed in radians.
  • The opposite is the COS() function.


  1. ACS(Number)


  1. arc cosine of (-1) happens to be Pi (3.14159....). Hence useful functions.
  2. ACS(Number) defined only for -1<=Number<=1 (otherwise, you'll get "out of range" error).
  3. Most mathematical operations in Just BASIC can be performed on Literal Numbers, Numeric Variables, or Numeric Expressions that consist of Literal Numbers, Numeric Variables, or both.
  4. There are 2 * pi radians in a full circle of 360 degrees. A formula to convert degrees to radians is: radians = degrees divided by 57.29577951.


Print ACS(1)
Print ACS(0.5)
Print ACS(-0.2)
Print ACS(-1/2)

Useful Functions

Calculating PI

function Pi()
    Pi= acs(-1)
end function

Converting Degrees to Radians

function deg2rad(angle) 'degrees to radians
    deg2rad = angle*acs(-1)/180     'angle*Pi/180
end function

Converting Radians to Degrees

function rad2deg(angle) 'radians to degrees
    rad2deg = angle*180/acs(-1)     'angle*180/Pi
end function