Practice problem
Compute the Picard group of the spectrum of the ring R[x,y]/(x2+y2−1).\mathbb{R}[x,y]/(x^2+y^2-1).R[x,y]/(x2+y2−1).
The Picard group cannot be generated by a single element.
Z\mathbb{Z}Z
Z/2Z\mathbb{Z}/2 \mathbb{Z}Z/2Z
The Picard group is trivial.
Hint please.
Type a concept, like “slope” or “photosynthesis”.