2021-04-29 21:13:30 +0200 received badge ● Notable Question (source) 2020-10-15 21:31:44 +0200 received badge ● Popular Question (source) 2020-05-24 17:24:24 +0200 commented answer Unexpected result for trigonometric function Sorry, I didn't take a screenshot. But admins can look at the logs. 2020-05-24 05:18:06 +0200 commented answer Unexpected result for trigonometric function Thanks for the reply. BTW, I was trying to post this question since yesterday, but it was being flagged as spam. Why is that? I am not behind proxy or anything. 2020-05-24 03:39:24 +0200 asked a question Unexpected result for trigonometric function I'm trying to solve the following trig eqn using sage. $$sin(x)-cos(x) = 0$$ Hand calculation give me the result of: $$x=\frac{\pi}{4} + n\pi$$ However, the solve() function gives me a different result, why is that?: sage: sage: solve(sin(x)-cos(x) == 0, x, to_poly_solve=True) [x == 1/4*pi + pi*z25] sage:  Also, what's z in the answer? I haven't defined any such variable. 2020-05-20 07:57:03 +0200 asked a question How to calculate twos and ones complement? How can I calculate twos and ones complement in sage? I tried searching the docs but didn't find anything. 2020-05-09 06:50:16 +0200 commented answer Solving quadratic inequality Thanks, I didn't notice it. 2020-05-08 19:40:27 +0200 commented answer Solving quadratic inequality but the answer doesn't contain the last part (2, 6) 2020-05-08 19:31:51 +0200 asked a question Solving quadratic inequality How to solve the following quadratic inequality: $$0.3 < \frac{2x}{x^{2} + 4} <0.5$$ The call to solve function return the following output: sage: sage: solve( [(2*x / (4+x**2)) < .5 , (2*x / (x**2 + 4)) > .3 ], x, to_poly_serve=True ) [[-2*x/(x^2 + 4) + 0.5 > 0, 2*x/(x^2 + 4) - 0.3 > 0]] sage:  By hand calculation I found the following answer $(2/3, 2) \cup (2, 6)$. 2020-04-26 11:53:52 +0200 commented answer How to correctly plot x^(1/3) So, its a function to plot relations rather than function. Thanks 2020-04-25 19:32:10 +0200 commented answer How to correctly plot x^(1/3) what's the difference between plot and implicit_plot? 2020-04-25 18:47:56 +0200 received badge ● Nice Question (source) 2020-04-25 17:08:30 +0200 commented answer How to correctly plot x^(1/3) How you arrive at this function sgn(x)*abs(x)^(1/3)? 2020-04-25 16:03:54 +0200 commented answer How to correctly plot x^(1/3) Specifying these arguments still doesn't plot the correct graph. 2020-04-25 16:02:09 +0200 commented question How to correctly plot x^(1/3) I was expecting this 2020-04-25 13:53:08 +0200 asked a question How to correctly plot x^(1/3) sage: plot(x**(1/3)) This command produces a graph that looks like this: I was expecting a graph like this: 2020-04-18 08:19:52 +0200 commented answer Unexpected result in calculating limits BTW, I don't quite understand the term "complex plane" and how the square root converges to 0. Where I can read more about it? 2020-04-17 13:35:34 +0200 commented answer Unexpected result in calculating limits is there any way to alter this behavior? 2020-04-15 13:43:24 +0200 asked a question Unexpected result in calculating limits Limit of sqrt(x-3) when x approaches 3 doesn't exist but the sage returns 0. Why is that? sage: sage: limit(sqrt(x-3), x=3) 0 sage:  2020-04-13 15:20:14 +0200 commented answer Sage returning wrong derivative Got it thanks :) 2020-04-13 07:05:48 +0200 commented answer Sage returning wrong derivative exp(1)**(x*y) and exp(x*y) both yields e^(x*y(x)). So, I think my equation is correct. Also, why I need to call the subs method. I used the same procedure to find the derivative of many equations. 2020-04-12 19:25:28 +0200 asked a question Sage returning wrong derivative I am trying to calculate the derivative of y = e^(x*y) Hand calculation give me the result of dy/dx = ( y*e^(x*y) ) / ( 1 - x*e^(x*y) ) But the sage is giving me the wrong output of -y/x. Here is my code: sage: sage: y=function('y')(x) sage: y y(x) sage: sage: expr = exp(1)**(x*y) sage: sage: diff(y) diff(y(x), x) sage: sage: diff(expr) (x*diff(y(x), x) + y(x))*e^(x*y(x)) sage: sage: solve(diff(expr), diff(y)) [diff(y(x), x) == -y(x)/x] sage: sage:  2020-03-11 07:25:15 +0200 received badge ● Citizen Patrol (source) 2020-03-11 07:24:49 +0200 edited question Calculating inverse of a function Is there any straightforward way to calculate inverse of a function in sage? For example: f(x) = 2 * x - 1 f^-1(x) = ( x + 3 ) / 2  I have encountered solutions like this. But this was answered 9 years ago, I hope there exist a better way to do now.