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mathnet / mathnet-symbolics

Math.NET Symbolics
http://symbolics.mathdotnet.com
MIT License
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About inverse trigonometric functions #41

Closed diluculo closed 6 years ago

diluculo commented 6 years ago

I think the differential formulas of the inverse trigonometric functions are incorrect. I'm not familiar with F#, but Calculus.fs needs to be modified as follows:

    let rec differentiate symbol = function
        ...
        | Function (Asin, x) -> (1Q / sqrt(1Q - pow x 2Q)) * (differentiate symbol x)
        | Function (Acos, x) -> (-1Q / sqrt(1Q - pow x 2Q)) * (differentiate symbol x)
        | Function (Atan, x) -> (1Q / (1Q + pow x 2Q)) * (differentiate symbol x)
FoggyFinder commented 6 years ago

It seems like you are right. Maybe you want to send PR with fix and tests?