Name
Atan Function
Class
System.Math
Syntax
Math.Atan(d
)
-
d
Use: Required
Data Type: Double or any valid numeric expression
A number representing a tangent
Return Value
A Double that is the arctangent in radians of
d
, in the range -pi/2 to pi/2
Description
Takes the ratio of two sides of a right triangle
(d
) and returns the corresponding angle in
radians. The ratio is the length of the side opposite the angle
divided by the length of the side adjacent to the angle.
Rules at a Glance
If
d
is out of range, the function returnsNaN
.This is a Shared member, so it can be used without creating any objects.
Example
Private Sub Main( ) Dim dblSideAdj As Double Dim dblSideOpp As Double Dim dblRatio As Double Dim dblAtangent As Double dblSideAdj = 50.25 dblSideOpp = 75.5 dblRatio = dblSideOpp / dblSideAdj dblAtangent = Math.Atan(dblRatio) 'convert from radians to degrees dblDegrees = dblAtangent * (180 / 3.142) MsgBox dblDegrees & " Degrees" End Sub
Programming Tips and Gotchas
To convert radians to degrees, multiply radians by 180/pi.
Do not confuse
Atan
with the cotangent.Atan
is the inverse trigonometric function ofTan
, whereas the cotangent is the reciprocal of the tangent.
VB .NET/VB 6 Differences
The Atan
function corresponds to the VB 6
Atn
intrinsic function.
See Also
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