Carrotsticks' Solutions 2015 Extension 1 HSC (4 Viewers)

[Carrotsticks]

I left it like this and this

You would've lost a mark for (i) (you provided the entire term, but they are looking for just the coefficient) but gotten full marks in (ii) (you provided the term/coefficient, same thing anyway here, and they're asking for the term).

 

[Pab]

You would've lost a mark for (i) (you provided the entire term, but they are looking for just the coefficient) but gotten full marks in (ii) (you provided the term/coefficient, same thing anyway here, and they're asking for the term).

shieeeeeeeeeeeeeeet

 

[My two cents]

Would you lose a mark for the forgetting the Plus C on a indefinite integral?

 

[QuantumRoulette]

What answer did you acquire for Q14 (a) (ii) then?

I got arctan((3g-4)/(sqrt(3)*g)) and I said since what is inside the arctan is positive, due to g being negative, that the acute angle is positive.

 

[Carrotsticks]

Would you lose a mark for the forgetting the Plus C on a indefinite integral?

Highly unlikely.

One mark would be allocated for identifying the relevant double angle formula, and the other mark would be allocated to finding the correct primitive.

By awarding you only 1 mark for not having a +C, they're categorising you as a student who could only identify the double angle formula and no more, which is ridiculous.

I got arctan((3g-4)/(sqrt(3)*g)) and I said since what is inside the arctan is positive, due to g being negative, that the acute angle is positive.

You would've lost a mark.

Also, in Extension 1, we use g=9.8 not g=-9.8. The direction is assigned manually, which is why y double dot = -g in the derivation of the equations of projectile motion.

 

[Drsoccerball]

If the person coming second gets X as a mark but the person coming first doesn't get higher than X what happens?

Can that second person still state rank ?

 

[InteGrand]

If the person coming second gets X as a mark but the person coming first doesn't get higher than X what happens?

Can that second person still state rank ?

Yes.

 

[Drsoccerball]

Yes.

Is it harder though?

 

[Carrotsticks]

If the person coming second gets X as a mark but the person coming first doesn't get higher than X what happens?

Can that second person still state rank ?

Your question is a bit ambiguous currently. What do you mean by 'second person'. The second person in your description, or the person coming second?

Just use person A and B.

 

[Drsoccerball]

Your question is a bit ambiguous currently. What do you mean by 'second person'. The second person in your description, or the person coming second?

Just use person A and B.

Person A is 1st and person B is 2nd. If B gets a mark > A does B have a possibility of stateranking>

 

[IamKirby]

In the question with v^2 = n^2(a^2 - (x-c)^2) I think I left both a and n as +- even though I got the right values. Will I lose the mark for this?

 

[InteGrand]

Is it harder though?

Just get 100%.

 

[InteGrand]

In the question with v^2 = n^2(a^2 - (x-c)^2) I think I left both a and n as +- even though I got the right values. Will I lose the mark for this?

Not sure, but they said the constants are positive.

 

[Carrotsticks]

Person A is 1st and person B is 2nd. If B gets a mark > A does B have a possibility of stateranking>

Yes. I can confirm that Person B can state rank.

Source: I came first in Biology at my school (as well as 4U maths, they're not mutually exclusive contrary to popular belief!). The guy coming 3rd internally got a state rank in Biology whereas I didn't, despite me coming first internally. However, my assessment mark in Biology became a beautiful 98 thanks to him!

 

[Drsoccerball]

Yes. I can confirm that Person B can state rank.

Source: I came first in Biology at my school (as well as 4U maths, they're not mutually exclusive contrary to popular belief!). The guy coming 3rd internally got a state rank in Biology whereas I didn't, despite me coming first internally. However, my assessment mark in Biology became a beautiful 98 thanks to him!

well it sucks that my ranks are crap for everything ahahah

 

[Carrotsticks]

In the question with v^2 = n^2(a^2 - (x-c)^2) I think I left both a and n as +- even though I got the right values. Will I lose the mark for this?

Most likely you would've lost only 1 mark for it, considering that they explicitly specified that a, c and n are positive constants in the question.

 

[IamKirby]

Not sure, but they said the constants are positive.

Damn, probably won't get it then. Don't know why I always skim read the questions -.- Looking at 69/70 now unless I made silly mistakes.

 

[kenny777777]

Would I get 0 or 1 out of 2 marks for:

12. b) ii) Finding p=4 but not finding Q

12. c) ii) Finding OB and using the cosine rule but using angle BOA, hence unable to find h.

14. c) iii) Finding the sum but not multiplying the entire thing 2^(2n+1)

 

[invisible036]

For q11e, it said evaluate, i left my answer in 2.decimal places, got 0.44, will i lose a mark?

 

[Carrotsticks]

Would I get 0 or 1 out of 2 marks for:

12. b) ii) Finding p=4 but not finding Q

12. c) ii) Finding OB and using the cosine rule but using angle BOA, hence unable to find h.

14. c) iii) Finding the sum but not multiplying the entire thing 2^(2n+1)

12 (b) (ii): Only one mark.

12 (c) (ii): Possibly zero marks, 1 if generous.

14 (c) (iii): If the sum was correct, then you may still get 2 marks considering the location of the question in the paper (as a general rule of thumb, the later into the paper, the more generous the marking).