- #1

Rorschach

- 10

- 0

Could someone tell me how we quickly determine that $R$ can be written as: $R = \left\{\theta \in [0, \pi/2], \phi \in [0, \pi/2], r \in [0,1]\right\}$?

I get that $r \in [0,1]$. But I don't know how to determine $\phi$ and $\theta$. I'd prefer an algebraic explanation, if possible.