The reciprocal of tangent is not a constant function, but Sage says otherwise. This is now http://trac.sagemath.org/sage_trac/ticket/3980 .
(Incidentally, using z(x)=tan(x) also doesn't work, as it yields a NotImplementedError (whose message could be better) for 1/z; presumably the bug below would occur even if it were implemented, though.) - kcrisman sage: z=tan sage: z tan sage: 1/z 1/tan sage: find_root(1/z,1,2) --------------------------------------------------------------------------- RuntimeError Traceback (most recent call last) <snip> /Applications/sage/local/lib/python2.5/site-packages/sage/numerical/ optimize.py in find_root(f, a, b, xtol, rtol, maxiter, full_output) 52 """ 53 try: ---> 54 return f.find_root(a=a,b=b,xtol=xtol,rtol=rtol,maxiter=maxiter,full_output=full_output) 55 except AttributeError: 56 pass /Applications/sage/local/lib/python2.5/site-packages/sage/calculus/ calculus.py in find_root(self, a, b, var, xtol, rtol, maxiter, full_output) 3088 return a 3089 else: -> 3090 raise RuntimeError, "no zero in the interval, since constant expression is not 0." 3091 var = repr(w[0]) 3092 RuntimeError: no zero in the interval, since constant expression is not 0. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---