Opened 9 years ago

# trig case where to_poly_solve True works, but not force

Reported by: Owned by: kcrisman burcin minor sage-6.4 symbolics mjo N/A

```solve(sin(x)/cos(x)==1,x,to_poly_solve='force')

This gives an empty list.  I know it has at least one solution, namely pi/4.
```

Note that `to_poly_solve=True` does work.

This is basically the same as this ask.sagemath question, by the way.

```sage: solve(tan(3*x)==1, x, to_poly_solve='force'
[]
```

We're basically silently failing since we can't translate `%solve` output from Maxima.

```(%i5) load(to_poly_solve);

(%o5) /Users/.../sage-6.9/local/share/maxima/5.35.1/share/t\
o_poly_solve/to_poly_solve.mac
(%i6) %solve(tan(3*x)=1,x);
2 %pi (12 %z11 + 1)
(%o6) %union(%if(3 tan (-----------------) - 1 # 0,
12
%pi
- 2 %pi %z11 - ---
6
[x = - ------------------], %union()),
2
2                        2 %pi       2 %pi
%if(3 tan ((4 %pi %z7 - %i log(sin (---) + cos (---))
12          12
%pi                      %pi
(sqrt(3) + 1) sin(---) + (sqrt(3) - 1) cos(---)
12                       12
+ 2 atan(-------------------------------------------------) + 2 %pi)/4) - 1 #
%pi                        %pi
(sqrt(3) - 1) sin(---) + (- sqrt(3) - 1) cos(---)
12                         12
%pi        %pi                %pi        %pi
sqrt(3) sin(---)   sin(---)   sqrt(3) cos(---)   cos(---)
12         12                 12         12   2
0, [x = - (%i (log((---------------- + -------- + ---------------- - --------)
3/2            3/2            3/2            3/2
2              2              2              2
%pi        %pi                %pi        %pi
sqrt(3) sin(---)   sin(---)   sqrt(3) cos(---)   cos(---)
12         12                 12         12   2
+ (---------------- - -------- - ---------------- - --------) )/2
3/2            3/2            3/2            3/2
2              2              2              2
%pi        %pi         %pi        %pi
sin(---)   cos(---)    cos(---)   sin(---)
12         12          12         12
sqrt(3) (-------- + --------)   -------- - --------
sqrt(2)    sqrt(2)     sqrt(2)    sqrt(2)
----------------------------- - -------------------
2                          2
+ %i (atan(---------------------------------------------------) + %pi))
%pi        %pi         %pi        %pi
sin(---)   cos(---)    sin(---)   cos(---)
12         12          12         12
sqrt(3) (-------- - --------)   -------- + --------
sqrt(2)    sqrt(2)     sqrt(2)    sqrt(2)
----------------------------- - -------------------
2                          2
2
- 2 %pi %z7)/2], %union()), %if(3 tan ((4 %pi %z9
%pi                      %pi
(sqrt(3) - 1) sin(---) + (sqrt(3) + 1) cos(---)
12                       12
+ 2 atan(-----------------------------------------------)
%pi                      %pi
(sqrt(3) + 1) sin(---) + (1 - sqrt(3)) cos(---)
12                       12
2 %pi       2 %pi
- %i log(sin (---) + cos (---)))/4) - 1 # 0,
12          12
%pi        %pi                %pi        %pi
sqrt(3) sin(---)   sin(---)   sqrt(3) cos(---)   cos(---)
12         12                 12         12   2
[x = - (%i (log((- ---------------- + -------- - ---------------- - --------)
3/2            3/2            3/2            3/2
2              2              2              2
%pi        %pi                %pi        %pi
sqrt(3) sin(---)   sin(---)   sqrt(3) cos(---)   cos(---)
12         12                 12         12   2
+ (- ---------------- - -------- + ---------------- - --------) )/2
3/2            3/2            3/2            3/2
2              2              2              2
%pi        %pi         %pi        %pi
sin(---)   cos(---)    cos(---)   sin(---)
12         12          12         12
sqrt(3) (-------- + --------)   -------- - --------
sqrt(2)    sqrt(2)     sqrt(2)    sqrt(2)
+ %i atan2(- ----------------------------- - -------------------,
2                          2
%pi        %pi                 %pi        %pi
sin(---)   cos(---)            sin(---)   cos(---)
12         12                  12         12
-------- + --------   sqrt(3) (-------- - --------)
sqrt(2)    sqrt(2)             sqrt(2)    sqrt(2)
- ------------------- - -----------------------------)) - 2 %pi %z9)/2],
2                          2
%union()))
```

### comment:1 Changed 9 years ago by jdemeyer

• Milestone changed from sage-5.11 to sage-5.12

### comment:2 Changed 8 years ago by vbraun_spam

• Milestone changed from sage-6.1 to sage-6.2

### comment:3 Changed 8 years ago by vbraun_spam

• Milestone changed from sage-6.2 to sage-6.3

### comment:4 Changed 8 years ago by vbraun_spam

• Milestone changed from sage-6.3 to sage-6.4

### comment:5 Changed 6 years ago by kcrisman

• Description modified (diff)
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