vb中arcsin() 与 arccos() 分别是什么格式

没有,只有一个Atn()是VB反正切函数，VB不提供其他反三角函数，不过可以用下列公式导出：

反正弦

Arcsin(X) = Atn(X / Sqr(-X X + 1))

反余弦

Arccos(X) = Atn(-X / Sqr(-X X + 1)) + 2 Atn(1)

反正割

Arcsec(X) = Atn(X / Sqr(X X - 1)) + Sgn((X) - 1) (2 Atn(1))

反余割

Arccosec(X) = Atn(X / Sqr(X X - 1)) + (Sgn(X) - 1) (2 Atn(1))

arccosx可以表示为Atn(Sqr(1 - x ^ 2) / x)

下面是一个例子：

Const pi = 31415926

Private Sub Command1_Click()

Dim i As Single, j As Single

i = 05

j = Arccos(i)

Print i, j, j / pi 180

i = -05

j = Arccos(i)

Print i, j, j / pi 180

i = 0

j = Arccos(i)

Print i, j, j / pi 180

End Sub

Private Function Arccos(ByVal x As Single) As Single

If x = 0 Then

Arccos = 31415926 / 2

Else

Arccos = Atn(Sqr(1 - x ^ 2) / x)

If Arccos < 0 Then '注意

Arccos = Arccos + 31415926

End If

End If

End Function