# Cylindrical / Spherical Coordinates

1. Jan 27, 2013

### eurekameh

I'm trying to convert the below Cartesian coordinate system into cylindrical and spherical coordinate systems. For the cylindrical system, I had r,vector = er,hat + sint(e3,hat).
While I do have a technically correct answer for the spherical coordinate system, I believe, I was wondering if there was a way to simplify the expression 1/cos[tan^-1*(sint)]. Thanks.

2. Jan 27, 2013

### Staff: Mentor

$r=\sqrt{x^2+y^2+z^2} = \sqrt{1+\sin^2(t)}$?

3. Jan 27, 2013