Specialist Mathematics Examination 2 discussion

[presto]

I don't think there should be any asymptote. Can someone confirm this? Or would they mark both of us as correct? An asymptote is defined as a line or curve that a function approaches as one variable approaches infinity. If t was limited to between zero and 15, then the function is not approaching anything.

Let's hope they mark both of us right!

Yeah, I didn't put an asymptote either for the same reason.
But just to be safe, I rambled on a little bit in the space below the graph justifying my decision for not putting the asymptote and stating what the asymptote would be if it was not a restricted domain like that.

[~T]

Also, for the water ski question, the one that asked for when acceleration was equal to zero... I said to exclude the solution t=0, and put something along the lines of the following as my reasoning:

The question states that r is defined for "t seconds after passing the buoy", so t>=0 for r. Thus, the acceleration is only defined for t>0, and the solution t=0 can be excluded.

I presume they'll mark it as correct if you kept t=0, but is my reasoning above sufficient to explain why I excluded it?

[sin0001]

Did anyone get two co-ordinates for the Point of Inflection question? Itute only mentions 1 co-ordinate :/

[~T]

Did anyone get two co-ordinates for the Point of Inflection question? Itute only mentions 1 co-ordinate :/

If you just solved with a calculator it approximates a solution that is very close to the asymptote, because this point "flattens out" and the second derivative became extremely close to zero, but it's not a point of inflexion sorry! Was your value near 403?

[silverpixeli]

Did anyone get two co-ordinates for the Point of Inflection question? Itute only mentions 1 co-ordinate :/

If I recall correctly, the questions specifically asked for one of them. The zeroes of the second derivative were N=0 (never happens because the initial value was about 20) N=e^5 and N=e^6 (which is the limiting value, so again it doesnt happen until t=infinity which is basically never) leaving N=e^5 as the only valid point of inflection

[silverpixeli]

Also, for the water ski question, the one that asked for when acceleration was equal to zero... I said to exclude the solution t=0, and put something along the lines of the following as my reasoning:

The question states that r is defined for "t seconds after passing the buoy", so t>=0 for r. Thus, the acceleration is only defined for t>0, and the solution t=0 can be excluded.

I presume they'll mark it as correct if you kept t=0, but is my reasoning above sufficient to explain why I excluded it?

It sounds right from a 'the derivate isn't defined at end points' point of view, but since it's acceleration does it work like that?

[andyse7en17]

What was the answer for the complex domain question in MC? I chose (-pi/2, -pi/3) v (pi/6, pi/3)... but there should be (5pi/6, pi) as well. Was there an answer like that? 

[BubbleWrapMan]

What was the answer for the complex domain question in MC? I chose (-pi/2, -pi/3) v (pi/6, pi/3)... but there should be (5pi/6, pi) as well. Was there an answer like that? 

That answer was the "most correct", they didn't have the correct option there as nliu pointed out before. If they have any sense they'll give everyone marks for that, but of course that means they won't.

[Apink]

If you don't have the right amount of decimal places, do you lose one mark and that's it or do you lose one mark each time you don't have the right amount?

[andyse7en17]

That answer was the "most correct", they didn't have the correct option there as nliu pointed out before. If they have any sense they'll give everyone marks for that, but of course that means they won't.

That was really a pain... I actually spent the last 10 minutes thinking about that question... then when I walked out of the exam room I realized that I put 10 instead of 15 for initial velocity when calculate the range after leaving the ramp in the projectile question

[Stick]

So what do you guys think the A+ cutoff will be?

[~T]

It sounds right from a 'the derivate isn't defined at end points' point of view, but since it's acceleration does it work like that?

I've raised it before and I think nliu agreed with me (which is always promising) but yeah, I'm not entirely sure.

If you don't have the right amount of decimal places, do you lose one mark and that's it or do you lose one mark each time you don't have the right amount?

I don't think that's one of those things sadly, but you might be right. I know that's the case for leaving off "dx" in multiple integrals and stuff like that, so it wouldn't surprise me, but yeah I am under the impression you would lose the marks each time sorry.

So what do you guys think the A+ cutoff will be?

Pretty typical, 145-ish/160.

[Stick]

Pretty typical, 145-ish/160.

I'll either be looking at a low A+ or a high A then, methinks.

[abcdqd]

Any chance that the t value for the skiier question could be negative? I mean there were no restrictions on it, so could acceleration also have been 0 before he passed the marker point? (Haha I'm just trying to justify carelessly leaving n as an element of Z and not restricting it to positive integers). Also for the A+ cut-off, there have been a lot of mixed messages. A large portion of people didn't put both y=x and y=-x for the complex graph, do you guys think that may have lowered it to around 70?

[Apink]

I don't think that's one of those things sadly, but you might be right. I know that's the case for leaving off "dx" in multiple integrals and stuff like that, so it wouldn't surprise me, but yeah I am under the impression you would lose the marks each time sorry.

Yeah, now that I think of it, it's most likely everytime. I realised in the last few seconds I didn't use the correct amount of decimals for the angle between vector "a" and "c". I wrote 76 instead of 75.5 and didn't have enough time to change it. Hopefully that's the only question I lost marks for incorrect amount of decimals.