# Sample question: How do I compute symbolic integrals like $\int{sin(x) tan(x)} dx$

 3 (Sample question) How do I compute the integral of $sin(x) tan(x)$ in Sage? asked Aug 18 '10 William Stein 1369 ● 5 ● 19 ● 44 http://wstein.org/ Evgeny 51 ● 1 ● 4 ● 11

 6 First, make sure that you variable "x" is defined to be a symbolic variable: sage: var('x')  then you can use the integrate command: sage: integrate(sin(x)*tan(x), x) -1/2*log(sin(x) - 1) + 1/2*log(sin(x) + 1) - sin(x)  posted Aug 18 '10 schilly 267 ● 4 ● 5 ● 10
 5 In addition, symbolic functions have an integrate method. For example, given the function $f(x) = \sin(x)\tan(x)$, sage: var('x') sage: f = sin(x)*tan(x)  its symbolic integral is calculated like so: sage: f.integrate(x) -1/2*log(sin(x) - 1) + 1/2*log(sin(x) + 1) - sin(x)  Be sure to provide the variable you wish to integrate with respect to as an argument to integrate. posted Aug 18 '10 cswiercz 829 ● 5 ● 17 ● 33 http://www.cswiercz.info/ Evgeny 51 ● 1 ● 4 ● 11
 3 You can integrate sin(x)*tan(x) in Sage by using the integrate command: sage: integrate(sin(x)*tan(x), x) -1/2*log(sin(x) - 1) + 1/2*log(sin(x) + 1) - sin(x)  You can find some more examples in the tutorial. posted Aug 18 '10 Mike Hansen 3840 ● 21 ● 46 ● 84 Thankx for the link to the tutorial ;) schilly (Aug 18 '10)
 0 Sample answer: does TeX work, I wonder... $\int_0^{\infty} e^{-t^2} dt$ posted Aug 18 '10 Dima 246 ● 2 ● 9 No jsmath yet. We need to add it like on mathoverflow.net. William Stein (Aug 18 '10) well, if it is mathjax by default, formulas are inside  or . just a single $is a bad idea ^^ schilly (Aug 18 '10) single$ is used for inline tex, double for block-style. Evgeny (Oct 13 '10)
 0 $\sum 2$ great :-) like that !! can you get (integrate) this (live-preview) functionality into the sage notebook text editor (tiny-mce) somehow ? i'd like to see the formula there while typing if i double-click directly on a formula tinymce opens plus a box with latex source code. but only the first time. how about the box popping up each time i place the cursor into a latex formula and then showing the typeset math. at the moment i don't see the use of the box ... thanks for sage ... am loving it!!! regards Patrick I guess, I am asking in the wrong place - (maybe "mis-")using this forum as a scratch pad - but the suggestion I'm making is somehow connected with this ... (I reached here from a blog bost). So to be a bit more precise: I am actually talking about the sage notebook. I am wondering what this light grey window is really good for and suggesting an way to make use of it. posted Nov 02 '10 Patrick2000 1 ● 1 do you mean - how to access latex source for the equation here in this forum? Mouse over the formula and right-click. Then select "Show source". Evgeny (Nov 02 '10) Ehr - no - although that's also a real nice functionality i didn't know of (fancy menu shades! (but menu initially hidden under firefox default menu (ubuntu 10.04 - 64bit : http://oi56.tinypic.com/1hef4p.jpg))) Patrick2000 (Nov 03 '10)

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