<p>Yes, your school is really that bad - chances are that the teachers, starting from algebra and going up through precalculus, have been rather incompetent. The concepts of calculus are pretty easy to understand. 99% of calculus mistakes are because of algebra or trig errors. Chances are that without understanding algebra or trigonometry, students are having an incredibly difficult time performing well on the AP Calc exams.</p>
<p>Of course, it’s possible that the calc teacher at your school is incompetent and does not understand the exam rigor. The exam is designed to throw in tricks that many students will not be able to forsee and solve without having prior experience. Also, your teacher may commit a cardinal sin like not assigning homework (seriously, a precalc teacher at my school assigns no homework) or not finishing the curriculum.</p>
<p>Finally, it may be possible that the students in your school are extremely unmotivated. There are many calculus tutorial videos available on the Internet, and a motivated student should be able to teach himself the subject, even without a competent teacher. This is why you will be the first student in seven years to pass the AP Calculus AB exam - you seem motivated and bright.</p>
<p>Honestly, I learned straight from the Larson/Hostetler/Edwards textbook. KhanAcademy on YouTube has many solid tutorial videos that help clear up discrepancies.</p>