[split] Where are you up to in Methods

[Daenerys Targaryen]

Sign diagrams help determine the nature of a cubic graph. You substitute values prior and after critical points on the cubic graph, thus allowing you to determine the shape of the cubic. However, this is done much easily with calculus through the first derivative test and it is even more simple through the second derivative test. I like using the second derivative test, seeing as it's just easier rather then drawing up a table then subbing values (similar to a sign diagram, without a sketch though).
It's personal preference really, if you like the first derivative test go for it! I always fall back on it, if I am unsure about my result with a second derivative test!

Is this whole sign diagram stuff apart of derivative/differention stuff? or with drawing cubics?

[EspoirTron]

It's not apart of calculus, it's apart of the drawing cubics though (depends what textbook you use, mine doesn't mention it). It doesn't take long to learn and its straightforward, it helps if you didn't 'want' to use calculus to determine the nature of a graph etc. It's a lengthy technique and using a calculus methodology will slash the time it takes by half (in my opinion).

[Jeggz]

Is this whole sign diagram stuff apart of derivative/differention stuff? or with drawing cubics?

It's related to finding the nature of the curve - for instance if we know two stationary points and we want to find the shape of the curve based on this knowledge.

[simba]

Sup guys! Just wondering where your school is up to in methods? :O

We've just finished chapters 1-5 in MQ, and have the SAC for chapters 3, 4 and 5 on wednesday

[Daenerys Targaryen]

It's related to finding the nature of the curve - for instance if we know two stationary points and we want to find the shape of the curve based on this knowledge.

Can't you just do that from the equation?

[EspoirTron]

Can't you just do that from the equation?

I think it's a proof of the nature!

[hardworker]

Finished up to chapter 5 and have a SAC on all of these chapters next Friday. Teacher has told the class he doesn't expect anything good from the class on this SAC just told us to salvage what we can.

[Stick]

You're not allowed to use the second derivative test in Methods. My Specialist (who is also my Methods) teacher made this explicitly clear to us to use the table method in the Methods exam.

[pi]

I think you can use second derivatives actually, fairly sure it was in some vcaa bulletin.

[EspoirTron]

You're not allowed to use the second derivative test in Methods. My Specialist (who is also my Methods) teacher made this explicitly clear to us to use the table method in the Methods exam.

My methods teacher approved of it, I am pretty sure VCAA said it was okay as well (I used it last year in Unit 2 and it was fine). However, check with VCAA to confirm.
In the exam, I believe if it says 'Show using the first derivative test' that you would, if it just said 'Prove this point is a maximum' then either test should be fine. Again, I would confirm with VCAA.