# Evaluate the triple integral (with spherical coordinates)

1. May 14, 2012

### melihaltintas

1. The problem statement, all variables and given/known data
Firstly sorry for my bad english,i have a one question for you(İ try it but i didn't solve it )

2. Relevant equations

3. The attempt at a solution
i know problem will be solved spherical coordinates but i dont know how i get angles (interval) theta and fi ?
$$\int_{0}^{\infty}\int_{0}^{\infty}\int_{0}^{\infty}e^{-\sqrt{x^2+y^2+z^2}}\,dxdydz$$

Mod note: Fixed LaTeX. Read what tiny-tim said below.

Last edited by a moderator: May 14, 2012
2. May 14, 2012

### HallsofIvy

Staff Emeritus
Re: evaluate the tripple integral (with spherical coordinates)

You get the angles by thinking about what the spherical coordinate variables mean. $\phi$ is the angle from the positive z-axis to the negative x-axis and, to cover all space, would normally go from $0$ to $\pi$. Since you want z to stay positive, you want $\phi$ to go from $0$ to $\pi/2$. $\theta$ goes around a complete circle in the xy-plane in going from $0$ to $2\pi$. Since the first quadrant is 1/4 of that, $\theta$ goes from $0$ to $\pi/2$. Finally, there is no upper limit on the distance from the origin to any point in the first octant so $\rho$ goes from $0$ to $\infty$.

3. May 14, 2012

### tiny-tim

welcome to pf!

hi melihaltintas! welcome to pf!

don't try to put forum tags inside latex! …​

4. May 15, 2012

### melihaltintas

thanks a lot :)