Looking for the most challenging material that could be used to study for the AB exam. I’ve done Barrons, 5 steps, and Petersons and I think Princeton review already. Not looking to do that Art of Math stuff or whatever it is, preferably multiple choice but anything works.
Dr. Chung’s is pretty difficult. Multiple Choice Questions To Prepare For The AP Calculus AB Exam by Rita Korsunsky is accurate, but maybe not more difficult than the exam. You can also get old copies of the Stewart or Thomas textbooks on Amazon for like $5: they have lots of hard problems, but not specifically for the AP exam.