Comment #11 on issue 3149 by smi...@gmail.com: solve() could attempt logcombine when looking for solutions
http://code.google.com/p/sympy/issues/detail?id=3149

correction to comment 10 - solves with force=True

And the OP expressions behave as follows:

dsolve(2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), f(x), hint='1st_homogeneous
_coeff_best', simplify=True)
[f(x) == 2**(1/3)*(x**2/(C3 + sqrt(C4 + 4*x**6))**(1/3) - 2**(1/3)*(C1 + sqrt(C2 + 4*x**6))**(1/3)/2), f(x) == 2**(1/3)*(-2*x**2/(C1 + sqrt(C2 + 4*x**6))**(1/3) + 2**(1/3)*(-1 - sqrt(3)*I)*(C3 + sqrt(C4 + 4*x**6))**(1/3)/2)/(1 - sqrt(3)*I), f(x) == 2**(1/3)*(-2*x**2/(C1 + sqrt(C2 + 4*x**6))**(1/3) + 2**(1/3)*(-1 + sqrt
(3)*I)*(C3 + sqrt(C4 + 4*x**6))**(1/3)/2)/(1 + sqrt(3)*I)]
dsolve(2*x*f(x) + (x**2 + f(x)**2)*f(x).diff(x), f(x), hint='1st_homogeneous
_coeff_best', simplify=False)
log(f(x)) == log(C1) - log(3*x**2/f(x)**2 + 1)/3
solve(_,f(x))
[2**(1/3)*(x**2 - 2**(1/3)*(-C1**3 + sqrt(C1**6 + 4*x**6))**(2/3)/2)/(-C1**3 + s qrt(C1**6 + 4*x**6))**(1/3), 2**(1/3)*(-8*x**2 + 2**(1/3)*(1 - sqrt(3)*I)**2*(-C 1**3 + sqrt(C1**6 + 4*x**6))**(2/3))/(4*(1 - sqrt(3)*I)*(-C1**3 + sqrt(C1**6 + 4 *x**6))**(1/3)), 2**(1/3)*(-8*x**2 + 2**(1/3)*(1 + sqrt(3)*I)**2*(-C1**3 + sqrt( C1**6 + 4*x**6))**(2/3))/(4*(1 + sqrt(3)*I)*(-C1**3 + sqrt(C1**6 + 4*x**6))**(1/
3))]


--
You received this message because this project is configured to send all issue notifications to this address.
You may adjust your notification preferences at:
https://code.google.com/hosting/settings

--
You received this message because you are subscribed to the Google Groups 
"sympy-issues" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sympy-issues+unsubscr...@googlegroups.com.
To post to this group, send email to sympy-issues@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy-issues?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.


Reply via email to