2017-07-14 14:26:39 -0600 received badge ● Notable Question (source) 2016-10-03 06:01:11 -0600 received badge ● Famous Question (source) 2016-05-30 08:07:36 -0600 received badge ● Famous Question (source) 2016-01-30 21:51:06 -0600 received badge ● Famous Question (source) 2015-10-16 14:37:29 -0600 received badge ● Famous Question (source) 2015-10-13 08:24:35 -0600 received badge ● Good Question (source) 2015-07-31 14:16:57 -0600 received badge ● Notable Question (source) 2015-06-23 02:58:06 -0600 received badge ● Popular Question (source) 2015-01-14 02:43:39 -0600 received badge ● Famous Question (source) 2014-06-28 20:14:40 -0600 marked best answer bool returns false with arcsin(x) and 2*arctan(x/(1+sqrt(1-x^2))) The two expression should be equal but when I write bool(arcsin(x) == 2*arctan(x/(1+sqrt(1-x^2)))) it returns false. Any clue - Why it does that? Any get around? 2014-04-24 08:17:56 -0600 received badge ● Notable Question (source) 2014-01-01 04:13:35 -0600 received badge ● Famous Question (source) 2013-12-30 05:17:17 -0600 received badge ● Nice Question (source) 2013-11-26 08:48:06 -0600 received badge ● Notable Question (source) 2013-10-22 15:40:26 -0600 received badge ● Popular Question (source) 2013-05-11 09:05:42 -0600 received badge ● Popular Question (source) 2013-05-08 21:30:42 -0600 received badge ● Notable Question (source) 2013-04-23 15:15:44 -0600 received badge ● Notable Question (source) 2013-04-01 14:53:25 -0600 received badge ● Popular Question (source) 2013-02-12 17:59:11 -0600 received badge ● Famous Question (source) 2012-12-28 07:46:43 -0600 received badge ● Popular Question (source) 2012-11-23 05:53:57 -0600 received badge ● Famous Question (source) 2012-10-20 08:14:54 -0600 received badge ● Notable Question (source) 2012-06-29 18:13:03 -0600 received badge ● Popular Question (source) 2012-01-02 03:43:25 -0600 received badge ● Notable Question (source) 2011-12-20 06:02:37 -0600 received badge ● Famous Question (source) 2011-10-27 13:22:58 -0600 received badge ● Notable Question (source) 2011-08-18 04:11:23 -0600 received badge ● Notable Question (source) 2011-07-19 02:06:03 -0600 received badge ● Popular Question (source) 2011-06-14 01:17:34 -0600 received badge ● Popular Question (source) 2011-06-02 14:39:12 -0600 received badge ● Popular Question (source) 2011-05-03 16:41:39 -0600 received badge ● Popular Question (source) 2011-04-28 12:04:54 -0600 received badge ● Taxonomist 2011-03-16 05:13:20 -0600 asked a question integral of 1/x, tan x why integral ($1/x$, $x$) returns $log(x)$? Shouldn't it return $log(|x|)$. Similarly, integral$(tan(x),x)$ returns $log(sec(x))$ shouldn't it return $log(|sec(x)|)$. Can anyone explain? After previous post, I dig a little bit and find:  sage: equation=integral(1/x+x,x).real() sage: equation 1/2*real_part(x)^2 - 1/2*imag_part(x)^2 + log(abs(x)) sage:  Now, anyway to set real_part(x)=x and imag_part(x)=0 in "eq" and get the resultant "eq"? More>> sage: integral(1/(x^3-1),x).real() -1/3*sqrt(3)*real_part(arctan(1/3*(2*x + 1)*sqrt(3))) + 1/3*log(abs(x - 1)) - 1/6*log(abs(x^2 + x + 1))  Everything is fine in the above computation except the word "real_part". Anyway to get rid of that? 2011-02-28 06:45:13 -0600 asked a question x/x = 1 at x=0? How can I find that x/x is undefined at x=0? Or any way when I write x/x, it returns x/x instead of 1? 2011-02-17 11:24:38 -0600 asked a question maxima is eating up all the memory I am running a sage script that uses maxima_methods().exponentialize(). I have a time out wrapper that kills the sage after a specific amount of time say 20 secs. Normamly when I kill sage, the associated process including maxima are killed. But, in a case, it kills the sage but not the associated maxima process. And the maxima process is eating up all the memory. Any way to kill that associated maxima process when I kill the sage script. Shoud I need to change/tweak anything in the file sage/interfaces/maxima.py 2011-02-13 19:42:34 -0600 received badge ● Nice Question (source) 2011-02-12 17:27:52 -0600 received badge ● Good Question (source) 2011-02-11 17:26:01 -0600 received badge ● Nice Question (source) 2011-02-11 07:16:51 -0600 asked a question arctan(tan(pi/2)) =pi/2 ? Sage evaluates tan(pi/2) to unsigned infinity which is true, but I want the above expression to work. Any way? When I apply arctan(tan(pi/2)) it gives error. Shouldn't it return pi/2. 2011-02-11 07:07:53 -0600 received badge ● Nice Question (source) 2011-02-11 06:19:00 -0600 asked a question any way to turn off error msg when I catch the errors? trying to check whether a numerical expression is NaN or not. My expression is log(arcsin(e)). If I apply N() on the expression it goes into infinite loop. I try to catch the runtime error. Everything seems to work in the following code except the error message displayed. I do not want that message in output. Any way to turn the error message off. sage: def number(expr): ....: try: ....: n = N(expr) ....: except (RuntimeError): ....: n = N(NaN) ....: return n ....: sage: expr=log(arcsin(e)) sage: a=number(expr) Exception RuntimeError: 'maximum recursion depth exceeded in __subclasscheck__' in ignored # I do not want the above error message in output sage: a NaN sage: a.is_NaN() True