• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

Maths Ext 2 Predictions/Thoughts (1 Viewer)

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
If that is the case then the answer is like this:
View attachment 33782

Was there something a bit more specific about the modulus of a+ib in the question?
Well assuming the reconstruction is approximately correct now, it is clear firstly that the argument of the first root is a quarter that of a+ib.

Secondly that the roots are equally spaced, hence on the lines perpendicular to each other.

Thirdly that the moduli of the roots are smaller than that of a+ib, but still greater than 1.

Fourthly that since a+ib is not a real number then the roots do not occur as conjugate pairs.

Not sure how the marks would be allocated though since it is just a 2 mark question.

This is why I wanted to know more about the modulus of a+ib. If there was something more specific about that, then maybe there might be a mark associated with that too.
 

imaiyuki

Active Member
Joined
Jul 22, 2019
Messages
14
Gender
Female
HSC
2021
Well assuming the reconstruction is approximately correct now, it is clear firstly that the argument of the first root is a quarter that of a+ib.

Secondly that the roots are equally spaced, hence on the lines perpendicular to each other.

Thirdly that the moduli of the roots are smaller than that of a+ib, but still greater than 1.

Fourthly that since a+ib is not a real number then the roots do not occur as conjugate pairs.

Not sure how the marks would be allocated though since it is just a 2 mark question.

This is why I wanted to know more about the modulus of a+ib. If there was something more specific about that, then maybe there might be a mark associated with that too.
i had to use my ruler to measure but it was exactly modulus 7/5 from origin, so i made all my four roots roughly (7/5)^(1/4) just to be safe, so just outside the unit circle
honestly idk if nesa were just being sneaky with making the modulus not 1
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
406
Gender
Female
HSC
1998
Surely its not just me whose reading this and cringing. Seems like everyones out here getting like 90 raws whilst im stuck with my poopy 60s/low 70s xD.

The only comfort im getting is the ability to do this again next year if it does go bum bum. Long story short, HSC is shitty :)

Regardless, good luck for x1 yall, they're prolly gonna be like last year, x1 harder than x2. So all of you getting raw 90s in x2 better watch out !
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
997
Gender
Male
HSC
2021
i think i lost at least 5 marks from silly mistakes (easy marks lost. not the only ones i lost obviously):
13b if you do trig sub (yes it works i did it again) you get a factor of 243 out the front. i forgot to carry this through so carried error, 1 mark
14a 4-x^2 = (4-x)(4+x). enough said, 1 mark
14bii forgot to write to 1 dp, 1 mark
15bii dont know if this is a mistake but after my expression which i know is correct, i forgot to write meters
16c forgot to label axes re(z) and im(z), also shading was a bit off.
 
Last edited:

tito981

Well-Known Member
Joined
Apr 28, 2020
Messages
325
Location
Orange
Gender
Male
HSC
2021
ive lost like 12 marks definite, probs aiming for like 85ish. I hope scaling is like 2013.
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
406
Gender
Female
HSC
1998
ive lost like 12 marks definite, probs aiming for like 85ish. I hope scaling is like 2013.
You reckon new syllabus ever going to compare to old syllabus, particularly 2013 aligning?? Surely not
 

CM_Tutor

Moderator
Moderator
Joined
Mar 11, 2004
Messages
2,642
Gender
Male
HSC
N/A
isnt z=-pi out of the principle argument domain
You are correct, so that means there should be open circles at and at and the boundary along the real axis between them should be dotted.

Good catch!
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
997
Gender
Male
HSC
2021
You are correct, so that means there should be open circles at and at and the boundary along the real axis between them should be dotted.

Good catch!
i suddenly have a newfound appreciation for the last question because there are so many intricacies. maybe i should've used my brain instead of just doing 2 graph inequality

kinda upset i didnt do it right because it seems so simple and logical looking back. probs gettin 1/3
 
Last edited:

Life'sHard

Well-Known Member
Joined
May 24, 2021
Messages
1,102
Gender
Male
HSC
2021
Uni Grad
2025
I was also pretty sad there weren’t any integration questions 🙁
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
406
Gender
Female
HSC
1998
yea did you do their 2021 papers or not? you would clearly see it’s much harder and very different
Different sure, idk about harder, as a couple people have said, there were a lot more 'easy' marks out to get, really dont think that was so much the case for the NSB 2021 paper, might just be personal strengths thing
 

tito981

Well-Known Member
Joined
Apr 28, 2020
Messages
325
Location
Orange
Gender
Male
HSC
2021
i suddenly have a newfound appreciation for the last question because there are so many intricacies. maybe i should've used my brain instead of just doing 2 graph inequality

kinda upset i didnt do it right because it seems so simple and logical looking back
yeah i feel with new syllabus they wont include as much conventional locus questions and it may be more need to be thought of more intuitively rather than algebraically.
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
997
Gender
Male
HSC
2021
yeah i feel with new syllabus they wont include as much conventional locus questions and it may be more need to be thought of more intuitively rather than algebraically.
ye reckon you can get 1 mark getting y=xtanx as a boundary and sketching it properly. but the shading part you really need to know your stuff.
 

AlphaBetaThetaGamma

New Member
Joined
Oct 25, 2019
Messages
10
Gender
Male
HSC
2017
yeah i feel with new syllabus they wont include as much conventional locus questions and it may be more need to be thought of more intuitively rather than algebraically.
16a was easy it was just cauchy schwartz inequality but then again im not a high school student.
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
997
Gender
Male
HSC
2021
for the projectile question just now i ended up with the result ??????. i used the exact same method i did in the test only now im calmer and more careful with my algebra but somethings not right obv. does anyone have a solution



dividing everything by t and simplifying:



 
Last edited:

Trebla

Administrator
Administrator
Joined
Feb 16, 2005
Messages
8,401
Gender
Male
HSC
2006
for the projectile question just now i ended up with the result ??????. i used the exact same method i did in the test only now im calmer and more careful with my algebra but somethings not right obv. does anyone have a solution
Maybe show your working?
 

Trebla

Administrator
Administrator
Joined
Feb 16, 2005
Messages
8,401
Gender
Male
HSC
2006
Well for starters it can’t be right as that is beyond the range for a sine function. The errors seems to be where you squared the constant term in your discriminant...
 

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

Top