# Chapter 12 - Parametric Equations, Polar Coordinates, and Conic Sections - 12.3 Polar Coordinates - Exercises - Page 618: 22

$$r=e\sec \theta$$

#### Work Step by Step

Given $$\ln x=1$$ Since $y=r\sin\theta,\ \ x= r\cos\theta,\ \ r^2=x^2+y^2$, then \begin{align*} \ln r\cos \theta&= 1\\ r\cos \theta&=e\\ r&=e\sec \theta \end{align*}

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.