Answer is: option2
\( x^2 + y^2 = y \)Solution:
If \( r = \sin \theta \), we multiply both sides by \( r \) to obtain \( r^2 = r \sin \theta \).
To convert to Cartesian coordinates, we replace \( r^2 \) with \( x^2 + y^2 \) and \( r \sin \theta \) with \( y \).
This gives \( x^2 + y^2 = y \).
