Here are the course descriptions at my school.
Algebra 2:
Topics studied include the properties, applications, algebra, and parametric representation of functions; matrix algorithms; and linear, quadratic, radical, exponential, logarithmic, polynomial, and rational functions.
Precalc:
Precalculus completes the formal study of the elementary functions begun in Algebra 1 and continued in Algebra 2. Students use the mathematical and modeling skills previously developed to study and apply the trigonometric functions. The use of technology and problem solving are emphasized in units covering data analysis, circular functions, and trigonometric inverses and identities. The concepts of trigonometry are extended to the study of polar coordinates and complex numbers. Conics and quadratic relations are introduced through a locus definition using polar representations. Discrete topics include the Principles of Mathematical Induction, the Binomial Theorem, and sequences and series, where sequences are represented both explicitly and recursively.