Chapter 8 - Section 8.1 - Polar Coordinates - 8.1 Exercises - Page 592: 18

R

This problem has many parts but the motive is to reduce the theta part to somewhere between $[-2\pi,2\pi]$. To do this we can add or subtract $2\pi$ since that is a complete rotation. So here, $-3\pi/4$ and 4. So $-3\pi/4$ is on the segment RP since if we rotate $3\pi/4$ radians clockwise on the unit circle we get to the point R. And 4 is positive so R is the answer.