If you need to know it, it's in this book. Cracking the ACT with DVD, 2012 Edition has everything you need to master the ACT exam, including:

‧ 4 full-length practice tests with detailed explanations—2 in the book and 2 online
‧ DVD featuring tutorials from The Princeton Review’s top course instructors
‧ Comprehensive and engaging review of content covered in all five sections of the ACT, including rhetorical skills and reading comprehension for English, geometry and trigonometry for Math, and experiments for Science Reasoning
‧ Detailed walk-through of how to write great essays
‧ Strategies for turning complex algebra into simple arithmetic
‧ Practice questions and explanations in every chapter
‧ Online lessons and tutorials for more practice