This document discusses rapid spectrum sensing algorithms for cooperative spectrum sensing in large cognitive radio networks. It begins with an introduction to cognitive radio and spectrum sensing. It then discusses optimizing cooperative spectrum sensing through determining the optimal voting rule, optimizing the energy detection threshold, and calculating the optimal number of cognitive radios needed. It also describes modeling spectrum sensing using energy detection and calculating the probability of false alarm and detection. Finally, it discusses the receiver operating characteristic of the "AND" voting rule under additive white Gaussian noise. The goal is to suggest a rapid spectrum sensing algorithm for large networks that requires fewer cognitive radios while achieving the necessary error rate bounds.