2U 2015 Discussion Thread (1 Viewer)

Flaming

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Didn't use similar triangles for 16c)i):

Took the bottom right angle as alpha
tan(alpha) = H/R
also, tan(alpha) = y / (R-x)

Equating, y = H/R * (R-x)
Substitute it in. etc.
 

photastic

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Yep, hands down more difficult than 2014 but definitely doable and easier than 2013, just a few tricky questions. I'd say alignment will be a bit better, maybe 79-82 will be the cut off for band 6.
 
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Mr_Kap

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Didn't use similar triangles for 16c)i):

Took the bottom right angle as alpha
tan(alpha) = H/R
also, tan(alpha) = y / (R-x)

Equating, y = H/R * (R-x)
Substitute it in. etc.
i tried that but gave up thinking it wasn't gonna work..

eventually i saw similar triangles but it was too late :(
 

Mr_Kap

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Yep, hands down more difficult than 2014 but definitely doable, just a few tricky questions. I'd say alignment will be a bit better, maybe 78-81 will be a band 6 cut off.
Pretty much just the triangle question part b, and the Find the volume 3 marker in q16 were hard.

I guess the last 4 marker could be clasified as 'hard' but it was just a routine process and algebra.

And in 2014 the only hard question was the finance question.
 

photastic

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Pretty much just the triangle question part b, and the Find the volume 3 marker in q16 were hard.

I guess the last 4 marker could be clasified as 'hard' but it was just a routine process and algebra.

And in 2014 the only hard question was the finance question.
And the finance question wasn't even that hard. Already a fan of this test so prob do it for fun later.
 

TQuadded

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Didn't use similar triangles for 16c)i):

Took the bottom right angle as alpha
tan(alpha) = H/R
also, tan(alpha) = y / (R-x)

Equating, y = H/R * (R-x)
Substitute it in. etc.
Holy crap I lost three marks for nothing. I started with this then I thought that it wasn't going to work. I'm a dumbass.
 

Mr_Kap

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And the finance question wasn't even that hard. Already a fan of this test so prob do it for fun later.
well if you never seen it before its pretty hard.

When i took the 2014 test yesterday that is what i lost two marks on out of three (and lost another two marks forgetting the plus c twice lol), so got 96/100
 

photastic

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well if you never seen it before its pretty hard.

When i took the 2014 test yesterday that is what i lost two marks on out of three (and lost another two marks forgetting the plus c twice lol), so got 96/100
LOL I did it last year for my HSC. I felt it was easy because we had much harder questions in our school exams so really schools should definitely place emphasise on hard questions to make the HSC feel relatively easier.
 

nerdz1

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I'm so confused about the circle inequality shading thing question... did you have to shade the 3rd quadrant or no? That's literally the hardest question in the entire exam for me ._.
Yes you need to shade part of the third quadrant. This is because despite the "range" of the semicircle function in the preceding question, the inequality expands beyond it (in fact I suspect the question was placed there as a means of tricking). If you observe here: http://www.wolframalpha.com/input/?i=+graph+y<sqrt(9-x^2) , it should be fairly clear.
 

Mr_Kap

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Yes you need to shade part of the third quadrant. This is because despite the "range" of the semicircle function in the preceding question, the inequality expands beyond it (in fact I suspect the question was placed there as a means of tricking). If you observe here: http://www.wolframalpha.com/input/?i=+graph+y<sqrt(9-x^2) , it should be fairly clear.
yeh i shaded the third quadrant and then thoguht i was wrong so redrew it only doin 1st and 2nd quadrant
 

nerdz1

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If u test a point (-1,-1) for y<= root (9-x^2) u would get undefined, so i don't think its in the 3rd quad.
You would not get an undefined value because of the x^2, which would make it sqrt(9 - (-1)^2) = sqrt(8), which works out.
 

nerdz1

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Well then fml... Would that only be -1 or -2 do you reckon?


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I think -1 realistically because it is technically only one error. They usually allocate 1M for one specific feature which needs to be included correctly e.g. axes + labelled graphs, scale...or something like that.
 

nerdz1

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for 15 c) ii] and iii] , I simplified 80/0.5 to be 40 instead of 160

would I get 1/2 for ii] and 0/1 for iii]

or since the concept was right, would it be 1/2 for ii] and 1/1 for iii]?
They should give you a "carry forward error" and pay the marks for (iii). :)
 

invisible036

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For the last part in the money question, I sub An=48500 instead of P, and i shown workings to get n = 168, can i still get 1/3?
 

Mr_Kap

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For the last part in the money question, I sub An=48500 instead of P, and i shown workings to get n = 168, can i still get 1/3?
not sure. Like you still did the process of expanding and blah blah blah and logs to find the months, and all that shit. So maybe depending on marking criteria you might get 1. I dont think youll get any though, but who knows
 

invisible036

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not sure. Like you still did the process of expanding and blah blah blah and logs to find the months, and all that shit. So maybe depending on marking criteria you might get 1. I dont think youll get any though, but who knows
Thanks, hopefully i can still get 92-94 raw. What do you think it will align to?
 

luhanbby

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Didn't use similar triangles for 16c)i):

Took the bottom right angle as alpha
tan(alpha) = H/R
also, tan(alpha) = y / (R-x)

Equating, y = H/R * (R-x)
Substitute it in. etc.
omg I did it like this too but in the spur of the moment I wrote sin alpha instead LOL fml will I get like 1/2 :(


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luhanbby

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if my raw mark is 92 (pretty sure it is since I've gone through the paper heaps and after reading this forum, I know everything I got wrong TT) what does the 'aligning' and stuff mean? will I get a 92 like on that thing you get for hsc results when you check on students online? tbh I don't even know where we check it LOL


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jazz519

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If i did a question then crossed it out and did the question in the last booklet for that particular question will they mark the attempt i made on the last booklet? was just wondering if it mattered if u did the questions in say 13 in order.
 

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