The Letters X and Y Represent Rectangular Coordinates $$y = x$$

Multiple Choice

The letters x and y represent rectangular coordinates. Write the equation using polar coordinates (r, θ) .
- $$y = x$$

A) $r = \cos \theta$
B) $\sin \theta = \cos \theta$
C) $\sin \theta = - \cos \theta$
D) $r = \sin \theta$