Maxima solve. :

 (C1) solve (x^2=1, x); (D1) [x 
= - 1, x = 1] (C2) solve(x^2-1,x); (D2) [x = - 1, x = 1] (C3) solve(log(x+3)=1, 
x); (D3) [x = %E - 3] 
:
 (C4) solve(sin(x)-1, 
x); SOLVE is using arc-trig functions to get a solution. Some solutions will be 
lost. %PI (D4) [x = ---] 2 
solve :
 (C5) s:[x+y+z=3, 
x+2*y-z=2, x+y*z+z*x=3]; (D5) [z + y + x = 3, - z + 2 y + x = 2, y z + x z + x 
= 3] (C6) solve(s, [x,y,z]); (D6) [[x = 1, y = 1, z = 1], [x = 7, y = - 3, z = 
- 1]] 

, Maxima :

 (C7) solve(x^2+1,x); (D7) 
[x = - %I, x = %I] 



ln(tg x) = 0.

,