Problem with acos



On Mon, 16 May 2011, Luigi Marino wrote:
> Maxima have?many?problems
> with trigonometric functions,
> it is not able to reduce
> acos(cos(x)) to x
> If you try all?trig simplification
> acos(cos(x)) is never ?x
Because acos(cos(x)) is not x!
It is the following function

                     ^
     /\        /\    |    /\        /\
    /  \      /  \   |   /  \      /  \
   /    \    /    \  |  /    \    /    \
  /      \  /      \ | /      \  /      \
/        \/        \|/        \/        \
------------------------------------------>

For example, acos(cos(x)) is an even function, because cos(x) is even.

Andrey