## University Calculus: Early Transcendentals (3rd Edition)

Polar equation: $r \cos \theta-r \sin \theta=3$ $r=\dfrac{3}{ \cos \theta- \sin \theta}$
Conversion of polar coordinates and Cartesian coordinates are as follows: a) $r^2=x^2+y^2 \implies r=\sqrt {x^2+y^2}$ b) $\tan \theta =\dfrac{y}{x} \implies \theta =\tan^{-1} (\dfrac{y}{x})$ c) $x=r \cos \theta$ d) $y=r \sin \theta$ Since, we have $x=r \cos \theta$ and $y=r \sin \theta$ Thus, we have an equivalent polar equation $r \cos \theta-r \sin \theta=3$