Dramatic slip in Pre-Cal, Dramatic increase in other classes

<p>Ok Overview: My school runs on trimester: In case you don't know, that is three 12 week semesters divided into 2 grading periods each (lasting 6 weeks). I am a senior (go class of '13!!)
Last Report card was about a few weeks ago and I got straight B's for the first time in High School. This I felt I was cheated somehow because I had an 89 in Pre-cal that time.</p>

<p>Now My classes are:
1.) Orchestra
2.) AP Lang
3.) AP Govt (lunch period)
4.) AP Chem
5.) Pre-cal</p>

<p>Ok as the title say I'm slipping hard in Pre-cal. I'm on the chapters with Sytheic and Long Division and "Graphs of Rational Functions" and I failed badly on the last 3 quizzes leaving my grade at a solid "F".
I never started that low before even this come as a shock to my friends as I got straight A's (even on the Finals) in last year Algebra 2. Many of them blamed it on senoritis but then I told them that I'm getting waay better in AP Chem and even my worst subject I got an A- (AP Lang)
I never really experience slip up like this before. I really wanted an A this grading period but this chapter is murdering my grade slowly but surely (there 2 sections left and we did like 5 already).</p>

<p>Am I losing my touch in math or I'm I going crazy? Also is anyone having this problem in any subject?</p>