2012 CSSA Maths 2U (4 Viewers)

[iBibah]

i had the idea that limiting sum was somehow involved but i did it wrong.

whats the reason why r=3/7x4/7?

Because the probability of Sophie winning is:

 

[Kimyia]

That circle question is the reason why you learn the proofs and derivations of things instead of rote learning (at mx1 kids)

Most mx1 students should have seen the proof before.

yeah, i noticed the rule we learnt in mx1 but i think all you had to do was equate two equations to prove it....?

 

[iBibah]

Can you (or anyone else) post up the probability question?

There are 4 red discs and 3 black discs in bag. Sophie and Emma play a game where they each have a turn at drawing a disc with replacement. Sophie starts.

Sophie wins when she draws a red disc and Emma wins when she draws a black disc.

(i) What's the probability that Sophie wins on the first draw?

(ii) What is the probability that Sophie wins in the first 3 draws. (either 3 or less)

(iii) What is the probability that Sophie wins the game

 

[iBibah]

Re: Thoughts on CSSA 2U Mathematics Exam??

I think it was 15 (a)....it was that cylinder one, proving the h

The only way I saw was to prove both triangles were similar than use sides in ratio, which was stupid for 2 marks.

 

[iBibah]

yeah, i noticed the rule we learnt in mx1 but i think all you had to do was equate two equations to prove it....?

Yeh not sure why so many got stuck when you found HK^2 twice, clearly you had to use it. People seem to forget that when they help you through a question, most likely every part will be used again in another part.

 

[Frostkruncher]

What were the solutions for the Q16 a velocity/time graph?

 

[rsagar]

Re: Thoughts on CSSA 2U Mathematics Exam??

Q15 and Q16 was done poorly by me...

I think out of 30. I probably got 9 or 10.
That's like dropped from 100 to 80 + extra errors might have not picked up
= 70-75/100 AH SHIT !!! There's goes my HSC

 

[Kimyia]

Re: Thoughts on CSSA 2U Mathematics Exam??

The only way I saw was to prove both triangles were similar than use sides in ratio, which was stupid for 2 marks.

yep, i did something along those lines. but i left that question to the very end so kinda rushed it :\

 

[Kimyia]

What were the solutions for the Q16 a velocity/time graph?

ooh, that was another question i really didnt get. they asked you what the velocity was at t=3 but you could only estimate (right?)

 

[iBibah]

ooh, that was another question i really didnt get. they asked you what the velocity was at t=3 but you could only estimate (right?)

Not really the graph was supposed to cut the x-axis at t=3. Hence the velocity was 0 at that point.

 

[Kostie100]

What was the answers to all the probability parts, anyone have them?

 

[Kimyia]

Not really the graph was supposed to cut the x-axis at t=3. Hence the velocity was 0 at that point.

grrr. i think i wrote something like it was approaching zero, but was close to like -0.5 or something. silly graph did not cross at t=3 :\ (...that or i was overthinking it)

 

[Frostkruncher]

Not really the graph was supposed to cut the x-axis at t=3. Hence the velocity was 0 at that point.

are you 100% sure the answer is v=0?, or did I have to estimate it?

 

[Kostie100]

grrr. i think i wrote something like it was approaching zero, but was close to like -0.5 or something. silly graph did not cross at t=3 :\ (...that or i was overthinking it)

I said velocity was 0 as well but it didn't look like exactly 0... stupid CSSA

 

[iBibah]

I said it was very close to the axis at t=3

Yeh it was close but a teacher told me that it's suppose to cut at 3. Bad graph imo.

I said velocity was 0 as well but it didn't look like exactly 0... stupid CSSA

yeh it was a really shit graph

 

[Kostie100]

Yeh it was close but a teacher told me that it's suppose to cut at 3. Bad graph imo

Was the first part of the probability qn just 4/7. Seems too easy...

 

[MATHmaster]

What was the answer to Q9 Multiple Choice: the one with the triangle with interior angle of (180-B) [once you use the angle sum of straight line to get there]
I used the sine rule but I'm not fully sure...

 

[UTRazilBay]

What did u guys get for the find the values of a,b and c. It was in an equation where instead of an equal sign their was a congruency sign

 

[Kimyia]

What was the answer to Q9 Multiple Choice: the one with the triangle with interior angle of (180-B) [once you use the angle sum of straight line to get there]
I used the sine rule but I'm not fully sure...

I think i said A because i thought sin(180-B) = -cos(B) and so used the sine rule with a + instead of a - to account for my negative angle. but hey, could be completely wrong

...thinking about it now, my reasoning seems completely wrong. oh well, one less mark

 

[2xL]

What did u guys get for the find the values of a,b and c. It was in an equation where instead of an equal sign their was a congruency sign

a = 3 b = 5 c = -8