Name
Atn Function
Syntax
Atn(number
)
number
Use: Required
Data Type: Numeric
Any numeric expression, representing the ratio of two sides of a right angle triangle.
Return Value
The return value is a Double representing the arctangent of
number
in the range -pi/2 to pi/2
radians.
Description
Takes the ratio of two sides of a right triangle
(number
) 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 no number is specified, a runtime error is generated.
The return value of Atn is in radians, not degrees.
Example
<% Const Pi = 3.14159 Dim dblSideAdj, dblSideOpp Dim dblRatio, dblAtangent, dblDegrees dblSideAdj = 50.25 dblSideOpp = 75.5 dblRatio = dblSideOpp / dblSideAdj dblAtangent = Atn(dblRatio) ' convert from radians to degrees dblDegrees = dblAtangent * (180 / Pi) Response.Write dblDegrees & " Degrees" %>
Programming Tips and Gotchas
To convert degrees to radians, multiply degrees by pi/180.
To convert radians to degrees, multiply radians by 180/pi.
Don’t confuse Atn with the cotangent. Atn is the inverse trigonometric function of Tan, as opposed to the simple inverse of Tan.
See Also
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