778 reputation
67
bio website
location
age
visits member for 3 years, 5 months
seen Jul 26 at 23:04

Aug
23
comment Mathematica 8 can not solve Eigenvalue problem
You will probably want to use NSolve instead of Solve. NSolve gives out numeric answers.
Jul
27
comment For what functions does $\int_{-\infty}^{\infty}x \sin(f(x))\,dx$ converge?
Now that you say it Sin(x^3+x) does become Cos(x^3) Sin(x) + Cos(x) Sin(x^3) which helps a ton. Thanks. I guess I was mostly hoping for some nice sufficient condition for a broad class of functions.
Jul
26
comment For what functions does $\int_{-\infty}^{\infty}x \sin(f(x))\,dx$ converge?
Yes. I was thinking of well behaved differentiable functions. By "grows fast enough" I assumed that a large enough Big O is what was necessary to guarantee that the integral converges. To make the issue more concrete, what polynomials f cause the integral to converge?