## Thomas' Calculus 13th Edition

The conversion of polar coordinates and Cartesian coordinates are described as follows: 1. $r^2=x^2+y^2$ and $r=\sqrt {x^2+y^2}$ 2. $\tan \theta =\dfrac{y}{x} \implies \theta =\tan^{-1} (\dfrac{y}{x})$ 3. $x=r \cos \theta$ and 4. $y=r \sin \theta$ Given: $\csc \theta=\dfrac{1}{\sin \theta}$ This implies that $r \sin \theta =4$ or, $y=4$ Thus, it shows a horizontal line 4 units above the x-axis.