General Thoughts: Mathematics Extension 1 (1 Viewer)

alexandred

New Member
Joined
Nov 8, 2011
Messages
29
Gender
Male
HSC
2013
Thought the paper was reasonable overall, thought with the exception of part c q14 was very easy (if induction can't be too hard so as to not favour 4u students, why make it part of the tail end of the paper?). The circle geo in q13 was pretty good for 3u, though once you saw the construction it becomes quite clear - I expect it will catch a lot of people who essentially assume the result, though. Don't think I dropped any.
 

Killerb47

Member
Joined
Feb 17, 2013
Messages
43
Gender
Male
HSC
2013
Hoping for 60/70. Damn circle geo cost me. Enough for 94/95 aligned mark??
 

Hotisgood5

New Member
Joined
Jul 25, 2012
Messages
18
Gender
Male
HSC
2013
Did anyone used the vertically opposite angles to prove the circle geometry question?
 

bangladesh

Well-Known Member
Joined
Nov 11, 2012
Messages
1,028
Gender
Male
HSC
2013
I didn't think it was too bad but i do 4u so.. But i could imagine that it would be quite challenging for a 2u student.
overall wasn't too bad, hopig for 90% raw.
 

iPhone4

Member
Joined
Nov 7, 2011
Messages
167
Gender
Undisclosed
HSC
N/A
Shit I went worse than expected. Got 64 in 2012 but hoping for 56-57 for this. Will that make an E4? 56/70?
 

alexandred

New Member
Joined
Nov 8, 2011
Messages
29
Gender
Male
HSC
2013
Did anyone used the vertically opposite angles to prove the circle geometry question?
What vertically opposite angles were there? We don't know qpt are collinear so how did you do it? Curious to see your solution.
 

hayabusaboston

Well-Known Member
Joined
Sep 26, 2011
Messages
2,387
Location
Calabi Yau Manifold
Gender
Male
HSC
2013
What vertically opposite angles were there? We don't know qpt are collinear so how did you do it? Curious to see your solution.
It said the line AT intersects C2 at B, so A,T,B are collinear. COnstruct line QP, then angle QTB let be alpha, then since ATB straight line, angle QTA is 180-alpha. Now angle ATP is also alpha, from vertically opposite angled QTB and ATp. This means QTP must be a straight line, and so Q, T and P collinear.

Thats what I did. AM I WRONG?> lol
 

RealiseNothing

what is that?It is Cowpea
Joined
Jul 10, 2011
Messages
4,591
Location
Sydney
Gender
Male
HSC
2013
It said the line AT intersects C2 at B, so A,T,B are collinear. COnstruct line QP, then angle QTB let be alpha, then since ATB straight line, angle QTA is 180-alpha. Now angle ATP is also alpha, from vertically opposite angled QTB and ATp. This means QTP must be a straight line, and so Q, T and P collinear.

Thats what I did. AM I WRONG?> lol
You're assuming QTP is a straight line, you can't do that.
 

alexandred

New Member
Joined
Nov 8, 2011
Messages
29
Gender
Male
HSC
2013
It said the line AT intersects C2 at B, so A,T,B are collinear. COnstruct line QP, then angle QTB let be alpha, then since ATB straight line, angle QTA is 180-alpha. Now angle ATP is also alpha, from vertically opposite angled QTB and ATp. This means QTP must be a straight line, and so Q, T and P collinear.

Thats what I did. AM I WRONG?> lol
Your proof goes: qpt is a straight line => qpt collinear. You effectively assumed the result,
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top