# Thread: Maths question from 2011 hsc Mathmatics.

1. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by girlworld_club
maths in focus. I just decided to do some questions from hsc 2011 ( it looked very easy at first, like that sort of sc question that you make up your own formula to solve a problem). But everything i tried it didn't work.
Worst textbook tbh lol. Make sure you supplement your learning with questions from other textbooks.

2. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by girlworld_club
like this question?
I don't think you'd need logs for this question. I'll show you another question later that requires logs.

3. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by Bored_of_HSC
Worst textbook tbh lol. Make sure you supplement your learning with questions from other textbooks.
what textbook do you suggest?

4. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by girlworld_club
what textbook do you suggest?
Fitzpatrick for 2U.

For other topics, use Terry Lee Fundamentals of Mathematics.

5. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by girlworld_club
I am a prelim student, trying to do some hsc work so excuse the unfamiliarity.

A skyscraper of 110 floors is to be built. The first floor to be built will cost $3 million. The cost of building each subsequent floor will be$0.5 million more than the floor immediately below.
(i)
What will be the cost of building the 25th floor?
2
(ii)
What will be the cost of building all 110 floors of the skyscraper?

To find out my answer i re-arranged to make this formula:
3,000,000 + (f x 500000) - 500000
where f = the number of floors

is this the right approach to answering the question, or does it produce the wrong answer? any other ways of doing it?
(i) t1 = 3 , d = 0.5 , t25 = 3 + 24× 0.5 = 15 , $15 million (ii) S110=110/2(2×3+109×0.5)=3327.5,$3327.5 million

6. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by 4025808
Fitzpatrick for 2U.

For other topics, use Terry Lee Fundamentals of Mathematics.
I got told Fitzpatrick is outdated. Is the Cambridge one any good?

7. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by carpe_diem
I got told Fitzpatrick is outdated. Is the Cambridge one any good?
Cambridge is very good IMO. There's a year 11 & 12 book. Some topics that are done in the year 11 MiF book may be covered in the Cambridge year 12 book. As for Fitzpatrick, it covers the whole 2 Unit Mathematics course. Take a look at this thread comparing textbooks.

8. ## Re: Maths question from 2011 hsc Mathmatics.

Use Cambridge/Fitzpatrick + Past paper. Really you don't need more than one textbook. I love out of date textbooks! Way more detailed! *Sighs* Computer generation...

Also there's no 2U "Fundamentals". It's strictly for 3U students.

9. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by girlworld_club
like this question?
Here's an example of a basic question in series that involves the use of logs.

Question:
The nth term of a series is given by the formula:
$t_{n} = 2^{n}-1$
Which term of the series is equal to 4095?

$4095 = 2^{n}-1$

$4096 = 2^{n}$

$4096 = 2^{n}$

$\ln 4096 = \ln 2^{n}$

$\ln 4096 = n\ln 2$

$\frac{\ln 4096}{\ln 2} = n$

$12 = n$

$\therefore 4096 \: is \: the \: 12th \: term \: of \: the \: sequence$

Note that:
$\ln = \log_{e}$

10. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by Gigacube
Here's an example of a basic question in series that involves the use of logs.

Question:
The nth term of a series is given by the formula:
$t_{n} = 2^{n}-1$
Which term of the series is equal to 4095?

$4095 = 2^{n}-1$

$4096 = 2^{n}$

$4096 = 2^{n}$

$\ln 4096 = \ln 2^{n}$

$\ln 4096 = n\ln 2$

$\frac{\ln 4096}{\ln 2} = n$

$12 = n$

$\therefore 4096 \: is \: the \: 12th \: term \: of \: the \: sequence$

Note that:
$\ln = \log_{10}$

11. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by SpiralFlex
Lol, I fixed it. I think.

12. ## Re: Maths question from 2011 hsc Mathmatics.

Strictly speaking you can't leave out a variable. When you are defining log base e to equal ln

$\ln x= \log_{e} x$

Sorry I am picky today. Be right back, more sugar.

13. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by SpiralFlex
Strictly speaking you can't leave out a variable. When you are defining log base e to equal ln

$\ln x= \log_{e} x$

Sorry I am picky today. Be right back, more sugar.
Thanks Spiral.

14. ## Re: Maths question from 2011 hsc Mathmatics.

Gum gum gum gum! Hehehehehe

I need to figure out the purpose of this thread, I forgot the title.

15. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by SpiralFlex
Gum gum gum gum! Hehehehehe

I need to figure out the purpose of this thread, I forgot the title.
Series!

16. ## Re: Maths question from 2011 hsc Mathmatics.

Originally Posted by Gigacube
Cambridge is very good IMO. There's a year 11 & 12 book. Some topics that are done in the year 11 MiF book may be covered in the Cambridge year 12 book. As for Fitzpatrick, it covers the whole 2 Unit Mathematics course. Take a look at this thread comparing textbooks.
Thanks! Really useful!

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