Maths Ext 2 Predictions/Thoughts (1 Viewer)

tywebb

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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

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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

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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

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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.
 
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tito981

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ive lost like 12 marks definite, probs aiming for like 85ish. I hope scaling is like 2013.
 

Jojofelyx

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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

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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

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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
 
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Life'sHard

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I was also pretty sad there weren’t any integration questions 🙁
 

Jojofelyx

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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

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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

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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

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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

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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:



 
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Trebla

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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

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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...
 

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