2013 CSSA Mathematics Thoughts? (3 Viewers)

[wagig]

The 2 mark probability, forgot the BH, BB, HB scenario, the clock chiming question I did 24 hrs instead of 12 and the question which asked for what values of y does this series not have an infinite sum. The play on words for the series questions screwed me as for a series to not have a infinite sum, means it has a limiting sum =( Sitting on 96/97

If a series has an infinite sum, that means that a concrete value (called the infinite sum) exists as the number of terms approaches infinity, i.e. a limiting sum, but if there is no infinite sum, that means the sum will just increase every time a new term is added, thus approaching infinity. Would this definition be right? D:

 

[NFmusic1995]

i thought of it as a normal analog clock but still if its on 3PM it will ding 15 times, it wasnt clear, i asked my teachr during the exam he said he cant tell me LOL

 

[dunjaaa]

An infinite sum does not equate to a concrete value. i.e. The sum just gets bigger and bigger, whereas a limiting sum has an actual value. That's the way I interpret it as, probably lost 1 mark for that question zzz

 

[JT145]

My school did Independent...

That was difficult as well (but I'm retarded at Maths so idk)

 

[AsianFrustratio]

That exam was pretty okay. We didn't have any motion and series questions since the 2 unit classes were behind

Question 16 (c) destroyed me :L I'll probably end up getting 3 or 4 out of 8. Did anyone manage to do the last question without double angle results (which is 3 unit). My friends who also do accelerated figured it out with 3 unit results, so I'm kinda curious to see how to do it with only 2 unit methods.

Also I might end losing my 2 unit ranking

 

[RealiseNothing]

An infinite sum does not equate to a concrete value. i.e. The sum just gets bigger and bigger, whereas a limiting sum has an actual value. That's the way I interpret it as, probably lost 1 mark for that question zzz

Yes it can. It just means you take infinite terms.

 

[mads21]

I find it strange that I found the question which had like 20 triangles inside one big triangle harder than Q16. Anyone else think that?

I got so caught up in that question, kinda bluffed it. Last question, got it except for the very last part on area. Just didn't get the chance to check through my answers :S

 

[anthony_wheels]

I got so caught up in that question, kinda bluffed it. Last question, got it except for the very last part on area. Just didn't get the chance to check through my answers :S

Haha, yeah I wasted so much time in the triangle one! Looking back now, I should have skipped it and spent time going back and checking my answers. I can't do much now, I just hope I didn't make any really bad mistakes. lol

 

[dunjaaa]

All you had to do was derive area in respect to theta, sub theta=pi/12 into dA/d(theta) and show that it equals 0, then test both sides and show that its max. Since r^2 is a constant and is always >0 then you can disregard the r^2 when it comes to testing. Thats the way you're meant to solve it in 2u.

 

[anthony_wheels]

All you had to do was derive area in respect to theta, sub theta=pi/12 into dA/d(theta) and show that it equals 0, then test both sides and show that its max. Since r^2 is a constant and is always >0 then you can disregard the r^2 when it comes to testing. Thats the way you're meant to solve it in 2u.

Beat me to it... I was trying to upload a photo from my phone. Does anyone know how to do it? or is it possible on a phone?

 

[bedpotato]

All you had to do was derive area in respect to theta, sub theta=pi/12 into dA/d(theta) and show that it equals 0, then test both sides and show that its max. Since r^2 is a constant and is always >0 then you can disregard the r^2 when it comes to testing. Thats the way you're meant to solve it in 2u.

Annoyed with myself for realising that 20 mins after the exam. How much was iii worth? 2 or 3 marks?

 

[Triage]

Beat me to it... I was trying to upload a photo from my phone. Does anyone know how to do it? or is it possible on a phone?

If you write down something wrong, but everything else is correct, are you correct? I solved dA/dthetaand proved it was a maxima using points surrounding it but then wrote some radom shit about end points. Will that lose me marks?

Oh and also, was the infinite sum one x > or = 1/2 ?

 

[bedpotato]

If you write down something wrong, but everything else is correct, are you correct? I solved dA/dthetaand proved it was a maxima using points surrounding it but then wrote some radom shit about end points. Will that lose me marks?

Oh and also, was the infinite sum one x > or = 1/2 ?

You'll probably get a mark for differentiating it properly.

I got y > 1/2 except y =/= 1. Probably wrong.

 

[AsianFrustratio]

Really? Fuck I feel even more stupid now haha.

 

[wagig]

If you write down something wrong, but everything else is correct, are you correct? I solved dA/dthetaand proved it was a maxima using points surrounding it but then wrote some radom shit about end points. Will that lose me marks?

Oh and also, was the infinite sum one x > or = 1/2 ?

Yeah I got the same for the infinite sum: y ≥ 1/2

 

[mac1996]

Yeah I got the same for the infinite sum: y ≥ 1/2

no, it was y>1/2

 

[coyney]

Yeah I got the same for the infinite sum: y ≥ 1/2

I got y > 1/2 and y=/= 1 (given)

 

[ebbygoo]

Hate to ruin people's days further, but Wagig pointed it out to me that the second 12hrs would be the next day... and so the sum would be 2x(that thing) - 12.

Made the same mistake :L

 

[ebbygoo]

Is it y>1/2 or y>=1/2???

 

[Triage]

Hate to ruin people's days further, but Wagig pointed it out to me that the second 12hrs would be the next day... and so the sum would be 2x(that thing) - 12.

Made the same mistake :L

It's 156