@Frigidcold You’re talking about after solving for the radius, correct? I thought you guys meant the one changes under certain conditions, which doesn’t. I understand, misunderstanding on my part. Thanks guys!
@Kazoo98 Assume the series is x^n/2^n then the ratio test would give abs(x/2)<1 so abs(x)<2 so the radius of convergence would be 2; however to find the interval of convergence, you have to test the outside points (in this case, -2 and 2) to see if they are convergent because when abs(x/2) = 1, or abs(x)=2, the ratio test doesn’t mean anything
Shell method isnt on the test
@hilariousbanana what? how do you know
Shell method is no longer on the ap test
my teacher said so and she is an ap grader this year. swear on my life
@hilariousbanana Where did you get that information from because I highly doubt they would remove it
I’ve been saying it’s not there, but don’t listen to me. Breaks my heart. 
I got that information directly from my teacher. She told our whole class and skipped shell method during our curriculum.
Do you guys recommend that we store formulas into our calculators or no?
@blargenshmargen: I can also affirm that the shell method is no longer in use. I swear I remember reading it in the guide with all the changes for the ‘new’ AP Calculus BC exam. Also, what formulas would you store in your calculator? There aren’t many hard ones that I know of.
I’m also still confused on how to determine the limits of integration for polar curves. For intersecting polar curves, do you set them equal to each other? And if there’s only one polar curve, what do you do? Does it all involve manipulating the ‘r’ in the equation of a polar curve??? If anyone has a useful video or link for an explanation, it would be greatly appreciated.
For the frq, there are a LOT of subtle hints on what to use. For example if you’re doing an accumulation type of problem (shoveling snow and there’s a graph, etc.) they may give you like “t(4)=2”. Then you know you have to use this information in an integral where integral of the derivative of a function from A to B= the function of A minus the function of B.
I also don’t believe I’ve EVER seen the newton-rhapson method in use during the calc bc exam, nor is it in my school textbook or ap prep book. I’m pretty sure it is not on the test, but please correct me if I’m wrong. And as others above have said, most solid revolution problems will use the washer method.
For the min/max frqs where there’s a graph, when do you have to ‘explore’ the endpoints? I’ve only seen it for absolute maximums and minimums, but I gues for relative min/max, you don’t have to?
Can anyone help me with the FRQ from 2005 Question 2 Part B? How do they find theta from the equation: (theta+sin2theta)*cos(theta)=-2 ?
Do we have to know newton’s method? I forgot the formula though I’m pretty sure it’s easy
The shell method is basically just a supplement method to the disk method. Shell is actually a lot easier since it’s direct rather than subtracting two components. It’s also parallel to the line, so the variable does not change (this is the reason why there is even two different methods – it’s more convenient to keep it in a certain variable). For example, if it’s difficult to set up an equation in terms of x and you’re revolving around x=0, then you shouldn’t put it in terms of x. You should use the disk method – that is perpendicular – instead.
I don’t understand what you mean by the intersecting polar curves. Do you mean like a cardioid or other polar curves, finding the area of a region? You would set up r=0, or use other methods. Like if you’re trying to see where it intersects at the y, then remember than y=rsintheta, or x=rcostheta. You can manipulate the r this way if you have one polar curve.
There is khanacademy video for this if you have not seen it already. I also have an answer key w/ problems to my textbook problems if you want the pdf file (pm me if you want it).
Remember the definition of derivatives! I’ve noticed quite few times on such problems like: f(3) = 5, what is f(6)=? That’s just the integral of f(x) from 3 to 6, and add 5. Of course, this may seem obvious but it’s not as obvious in word problems.
@blargenshmargen You basically set up columns of x, y, dy/dx, and delta y. They will tell you to do it in specific number of steps, say two. You are approximating from 1 to 2. Then your steps are simply 0.5. You are given a differential equation and a beginning point. So you have your (x,y) and dy/dx. So basically plug your x and y to find out what dy/dx is. Then, multiply dy/dx by 0.5 to find your delta y. Add your old y and delta y to find your new y.
I will be happy if I get a 2 on BC.
is newtons law of cooling on the test?
Do we need to know the derivatives of logx, arcsin/cos/tan, a^x