arccosx可以表示为Atn(Sqr(1 - x ^ 2) / x)下面是一个例子：Const pi = 3.1415926Private Sub Command1_Click() Dim i As Single, j As Single i = 0.5 j = Arccos(i) Print i, j, j / pi * 180 i = -0.5 j = Arccos(i) Print i, j, j / pi * 180 i = 0 j = Arccos(i) Print i, j, j / pi * 180 End SubPrivate Function Arccos(ByVal x As Single) As Single If x = 0 Then Arccos = 3.1415926 / 2 Else Arccos = Atn(Sqr(1 - x ^ 2) / x) If Arccos < 0 Then '***注意 Arccos = Arccos + 3.1415926 End If End IfEnd Function
