Hello..

I'm already knew there is no ArcCos or ArcSin in Visul Basic..

after searching on internet i've got this code..

Code:
Public Function Arccos(X) As Double
   If Round(X, 8) = 1# Then Arccos = 0#: Exit Function
   If Round(X, 8) = -1# Then Arccos = PI: Exit Function
   Arccos = Atn(-X / Sqr(-X * X + 1)) + 2 * Atn(1)
End Function
unfortunately, i dont know why the answer was wrong..

i try on calculator cos-1 (-0.7071) = 134.999

but when i use the code above, the result give me = 1.583137

PS: already use some kind like convert radiant to degree or reversal .. (*PI/180)

any help?