# Sample answers for the math papers (1 Viewer)

#### Run hard@thehsc

##### Well-Known Member
For the HSC 3u and 4u sample answers, can there be more than one way of getting the correct answer apart from the sample answer given in the marking guidelines?

#### d1zzyohs

##### Active Member
definitely, especially for ext 2.
an easy example could be proving the arithmetic mean stuff
$\bg_white x^2 + y^2\geq2xy \newline \text{This can be proven two ways; usually in exams you see} \newline \text{the use of arithmetic and geometric mean: } \frac{x+y}{2}\geq\sqrt{xy} \newline \text{However; it can be solved far easier; } \newline x^2-2xy+y^2\geq0 \newline (x-y)^2\geq0$
obviously this question is super easy - but I've seen this for inequalities where there is a domain... and could theoretically be proven by induction. I did that in the CSSA trials and got it correct.

#### jks22

##### Member
For the HSC 3u and 4u sample answers, can there be more than one way of getting the correct answer apart from the sample answer given in the marking guidelines?
Yes as long as it is within the scope of the syllabus

You can't however use MX1 techniques for ADV questions or MX2 techniques for MX1 questions

#### mmmmmmmmaaaaaaa

##### Well-Known Member
Yes as long as it is within the scope of the syllabus

You can't however use MX1 techniques for ADV questions or MX2 techniques for MX1 questions
Yes you can

#### asduiashdi

##### Active Member
Yes you can
i think for some identities that are outside the syllabus, you have to derive them right?

#### Run hard@thehsc

##### Well-Known Member
Yes you can
I do not think you can use MX2 techniques for MX1 tho - personally tried it out and I got penalised... Not sure about MX1 and Maths Advanced!

#### asduiashdi

##### Active Member
I do not think you can use MX2 techniques for MX1 tho - personally tried it out and I got penalised... Not sure about MX1 and Maths Advanced!
may i ask what was the technique and question?

#### mmmmmmmmaaaaaaa

##### Well-Known Member
I do not think you can use MX2 techniques for MX1 tho - personally tried it out and I got penalised... Not sure about MX1 and Maths Advanced!
i think for some identities that are outside the syllabus, you have to derive them right?
I've asked my teachers as well and they said yes

#### mmmmmmmmaaaaaaa

##### Well-Known Member
may i ask what was the technique and question?
I have used it mainly for integration techniques (4u in 3u and 3u in 2u)

#### asduiashdi

##### Active Member
I have used it mainly for integration techniques (4u in 3u and 3u in 2u)
ah okay thats cool, using 4u integration techniques would probably give you an advantage. but don't they design the exams so that you don't need 4u in 3u exams? i wonder if this is allowed in the actual hsc

#### Life'sHard

##### Well-Known Member
With anything math related there’s always more than one way of doing a question.

As for scope of syllabus, for things like cross product. I remember you were still able to use them however if you don’t get the same answer as the expected result the whole thing would be incorrect. You wouldn’t get partial marks. If someone could fact check me that’d be sweet.

#### mmmmmmmmaaaaaaa

##### Well-Known Member
ah okay thats cool, using 4u integration techniques would probably give you an advantage. but don't they design the exams so that you don't need 4u in 3u exams? i wonder if this is allowed in the actual hsc
No there was definitely another way to do it, I just thought by parts was easier. It was to integrate x(cos^-1x) or something like that

#### Run hard@thehsc

##### Well-Known Member
No there was definitely another way to do it, I just thought by parts was easier. It was to integrate x(cos^-1x) or something like that
ig you could use the differentiate then integrate method in this case - but by parts would be the obvious choice ig!