I'm studying for the SAT Math II and really love this resource, but essential topics are missing.

• Series (Arithmetic and Geometric)
• The Ellipse and Hyperbola conic sections
• Matrices
• Vectors

These are *essential* topics and probably what most people would get wrong on the subject test. If we want people to be prepared to their fullest then these topics should be added. They are in the precalc section of the site (that's how I've been studying them) but they should really by in the SAT Math II section as well.