> Try telling Symbolic Math Toolbox about any assumptions you're making about > the symbolic variables. In particular: > syms x m > syms p positive > > int(exp(-p*x^2),0,inf) > > For which, I should get the answer : > > 1/2*sqrt(pi/p) Thanks a lot!! Just what I was looking for. This does not seem to be documented in the help section. If it is, I have missed it. With this addition, I get the answer I want. Otherwise, I accept freely that my previous posts had some stupid omissions. syms m positive syms p positive > f=exp(-m/x^2-p*x^2) > integ=int(f,0,inf) But the above trick does not seem to work here. I suppose that, here, the limitations of the symbolic toolbox kick in. Right? Or, is it still possible to add more information to get at the solution?
Additionally, > So, try to perpetuate the expansion point a litle away from zero > > EDU>> taylor(exp(-m/x^2-p*x^2),x, 'ExpansionPoint',0.01,'Order',6) > > ans = > > exp(- 10000*m - p/10000) - exp(- 10000*m - p/10000)*(x - 1/100)^3*((300000000*m + > etc...
The above does not work for me. But the following command works fine : taylor(exp(-m/x^2-p*x^2),6,x,0.01)
This version is documented in the help. But the one with 'ExpansionPoint' and 'Order' is not (at least, not in R2009b). This is a minor point, but I would just like to make sure that I am looking at the right places in the documentation. Thanks, Ravi