# Carrotsticks' Extension 1 HSC 2013 Solutions (1 Viewer)

#### Makematics

##### hwpo13
I made the mistake of forgetting to quickly check with L'Hopital's on tuesday for mc 9, lost one mark.
THen I drilled into my head that I would definitely use L'Hopital's this time.

Next thing you know, I forget to put x^2 in differentiation a few parts later.
I never made a mistake in chain rule for a year until now. WTF.
product rule

#### anomalousdecay

product rule
Yeah no wonder. 4-unit integration has weakened me differentiation.
Surprisingly I resisted integrating today.
Only 4 integrals from memory I think.

#### Makematics

##### hwpo13
Yeah no wonder. 4-unit integration has weakened me differentiation.
Surprisingly I resisted integrating today.
Only 4 integrals from memory I think.
yeah haha, i remember before i first learnt integration i was nailing all these hard derivatives... never really needed them.

#### anomalousdecay

yeah haha, i remember before i first learnt integration i was nailing all these hard derivatives... never really needed them.
I know right. Come uni engineering, Minimums and Maximums of tensile strengths of metals represented by an imaginary number which represents the rate of change of charge (current) in material x, y, and z.

Luckily I didn't skip year 11 maths work.

Its amazing how far you can get in calculus in just one year though.

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#### Carrotsticks

##### Retired
I don't know why but I got 0.094 for the last question :-w :-w :-w
Most likely rounding errors from previous parts etc. Since you roughly got the right answer, I'm inclined to think that you probably had the right method too.

#### Reloman

##### New Member
Can someone explain how question 5 was A and not B?

#### iBibah

##### Well-Known Member
Can someone explain how question 5 was A and not B?
x=0.5(u-1) and du/2 = dx

#### Reloman

##### New Member
x=0.5(u-1) and du/2 = dx
Dam forgot to get rid of the dx when I was converting everything to u =.="

#### alexandred

##### New Member
I don't know why but I got 0.094 for the last question :-w :-w :-w
There are two methods once you have realized that rt ~= 0.56.
We have lnt = e^rt, but we also know e^rt = 1/rt.
Solving lnt = e^(0.56) gives 0.0972, solving lnt = 1/0.56 gives 0.094 (rounded from 0.0939 if memory serves). Either is an acceptable approximation (I suspect they'll both get paid).

#### superSAIyan2

##### Member
is my working out correct for the 3mark binomial question. It seems really different to carrotsticks'. Could someone predict what i should get out of 3?

#### RealiseNothing

##### what is that?It is Cowpea
is my working out correct for the 3mark binomial question. It seems really different to carrotsticks'. Could someone predict what i should get out of 3?

View attachment 28957
I did something similar by letting k=m.

#### HAX0R

##### Member
If your assessment mark is decent enough.

#### asianese

##### Σ
is my working out correct for the 3mark binomial question. It seems really different to carrotsticks'. Could someone predict what i should get out of 3?

View attachment 28957
It seems fine to me.. Should be 3/3.

##### New Member
Wow, looking at Carrotsticks' Results, when I'm only giving myself marks that I know for sure that I got I am on 40/70, and when I'm being generous I am on 47/70, which is still considerably lower than my trial mark of 60/70... Good thing I have misadventure for a personal matter then, I guess, but I was hoping I wouldn't need it...

#### iBibah

##### Well-Known Member
Wow, looking at Carrotsticks' Results, when I'm only giving myself marks that I know for sure that I got I am on 40/70, and when I'm being generous I am on 47/70, which is still considerably lower than my trial mark of 60/70... Good thing I have misadventure for a personal matter then, I guess, but I was hoping I wouldn't need it...
was that a commercial trial?

#### calze6

##### New Member
I also got 0.094 for the last question. I just used .56 in the rounding, I think I should be okay

#### superSAIyan2

##### Member
It seems fine to me.. Should be 3/3.
thanks, was getting worried i might have stuffed it up by not listing k=0,1,2...