Hmm. To be honest I don't know where to start. For example, how to i manage the position vector? Do i replace x, y, z with r cos \theta sin \phi etc, then do the divergence? It starts to look very messy ... t^{-\frac{5}{2}}e^{-\frac{r}{4kt}} r cos \theta sin \phi for the x component for example
Homework Statement
The density in 3-D space of a certain kind of conserved substance is given by
\[\rho (x,y,z, t) = At^{-\frac{3}{2}}e^{-\frac{r^2}{4kt}}\]
where \mathbf r = x\mathbf i + y\mathbf j +z\mathbf k and r = |\mathbf r|. The corresponding flux vector is given by
\mathbf...
it's always something simple isn't it..
area \frac{5}{x^{1.1}} * (x - (x-1)) < \int_{x-1}^x\frac{5}{x^{1.1}}dx
for all values of positive x, so the sum must be smaller than the integral
thanks for the tip
stu
Homework Statement
excuse my formatting.
compare
sum(from n=2 -> infinity) of 5/(n^1.1)
to
integral (from 1 -> infinity) of 5/(x^1.1)
Homework Equations
The Attempt at a Solution
if it was sum and integrate from 2 it would be easy... the sum is a rienmann sum using...