AP Calculus AB: Exam Prep Graph Analysis FRQs

[@samihatahsin7369]

I have to take the makeup exam on tuesday unfortunately, since summer already started for me I don't have any of my teacher's handy review sessions anymore, your videos were a huge help in making sure I don't forget all of calculus haha!

[@jsandov6]

Samiha, glad they helped!

[@ronaldthomas1484]

I personally want to thank for helping me learn calc at the last minute and I'm pretty sure I would have gotten a 1 without your help!

[@jsandov6]

Glad I could help Ronald!

[@marafryer5284]

1 min to exam

[@ColtraneTurnaroundBlues]

I get how g(x) does have point of inflection at x=4, but it always seems to me that f is not differentiable at 4, since it is a jagged line, but im probably wrong.

[@jsandov6]

EW, that's an excellent question! You are correct but the answer lies in the question. There is a critical point at x=4 but we cannot find the value of it because it's not differentiable. Think of the graph y=x^1/3....you can see the concavity at zero but you can't find the value at x=0 because it's not differentiable at that point. Hope this helps. Nice job of thinking, way to go! Looks like you'll do quite well on the exam:)

[@jessieriley5782]

wouldnt this only be true if the graph were of f prime and not f?

[@blobbloblbolb7995]

Sadly, the Ap exam does not take table of signs for justification so if you are going to take the Ap Calc Exam I would look at past exams to see what the Ap exam is looking for when using justification statements. "However, a sign chart will never earn students any points on the AP exam. Students should use sign charts when appropriate to help make determinations, but they cannot be used as a justification or explanation on the exam."

[@carlosjavier771]

How come for part c you didn't test g(2) or g(10)? After all, you did say they were candidates.

[@jsandov6]

CJ, x=2 and x=10 don't change from positive to negative or from negative to positive so its not a candidate for a minimum. It is a candidate b/c it's at zero but when we do our number line we see that it doesn't change sign, so that's why I don't use it. hope this helps!