use spherical coordinates to evaluate the triple integral of

Question

(e^-(x^2+y^2+z^2))/(sqrt(x^2+y^2+z^2)dV
where E is the region bounded by the spheres
x^2+y^2+z^2=49 and
x^2+y^2+z^2=81???

Answer 1

Integrate

exp(-r^2)/r 4 pi r^2 dr from r = 7 to r = 9