[Maxima-bugs] [maxima:bugs] #4628 %solve(abs(sin(x))=1, x) misses solutions

[David S. <tom...@us...>]

Interesting! One would think that solving `abs(f(x)) = c` is done by solving `f(x) = c` and `-f(x) = c` and then returning the union of the solutions. Apparently, this is not what's happening, because solving `sin(x) = 1` and `sin(x) = -1` yields only the real solutions.


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**[bugs:#4628] %solve(abs(sin(x))=1,x) misses solutions**

**Status:** open
**Group:** None
**Labels:** %solve 
**Created:** Sat Nov 01, 2025 08:50 PM UTC by Stavros Macrakis
**Last Updated:** Sat Nov 01, 2025 08:50 PM UTC
**Owner:** Barton Willis


<pre>
%solve(abs(sin(x))=1,x) =>
   %union([x = 2*%pi*%z3405-%i*log(sqrt(2)-1)],
                     [x = 2*%pi*%z3454-%i*log(sqrt(2)+1)])
</pre>
This is missing all the real solutions (namely %pi*(%z+1/2)) as well as many other complex solutions.


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