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March 29, 2024, 04:09:32 am

Author Topic: Mathematics Question Thread  (Read 1296802 times)  Share 

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jakesilove

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Re: Mathematics Question Thread
« Reply #585 on: October 18, 2016, 11:36:30 am »
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Can you help me with part (iv) and (v) please

Hey! Cool question, I think this was from my year's paper :)

We know that the equation for Carp population will be



From the information given. This means that the rate of increase in Carp will be



The rate of decrease in Trout is



Now, for part iv), we want these two rates to be equal! We absolute value them, because one is decreasing and one is increasing. So,







For the next part, we just set the numbers equal to each other



This is a tricky solution. BOSTES give fairly straight forward answers to this part.



Let me know if I can clarify anything!
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kevin217

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Re: Mathematics Question Thread
« Reply #586 on: October 18, 2016, 11:52:46 am »
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Hi, could someone provide me a solution for the second derivative in i).
Thanks

jakesilove

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Re: Mathematics Question Thread
« Reply #587 on: October 18, 2016, 12:06:20 pm »
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Hi, could someone provide me a solution for the second derivative in i).
Thanks

Hey! So we've got



To find the first derivative, we can just apply the chain rule to the second part



To find the second derivative, we can just apply the chain rule again.



As t is always positive, (1+t) will always be positive, and so (1+t)^(-3) will always be positive. Therefore, -2*positive will always be negative, as required.
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kevin217

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Re: Mathematics Question Thread
« Reply #588 on: October 18, 2016, 12:10:56 pm »
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Hey! So we've got



To find the first derivative, we can just apply the chain rule to the second part



To find the second derivative, we can just apply the chain rule again.



As t is always positive, (1+t) will always be positive, and so (1+t)^(-3) will always be positive. Therefore, -2*positive will always be negative, as required.
Sweet, thanks for the solution.

nimasha.w

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Re: Mathematics Question Thread
« Reply #589 on: October 18, 2016, 03:04:34 pm »
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hey! could someone please explain how you would do this question :-)

mfjw

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Re: Mathematics Question Thread
« Reply #590 on: October 18, 2016, 03:33:50 pm »
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Can someone help me with this question, please?

RuiAce

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Mathematics Question Thread
« Reply #591 on: October 18, 2016, 03:37:52 pm »
+1
Can someone help me with this question, please?


There. The indices are all positive now.

RuiAce

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Mathematics Question Thread
« Reply #592 on: October 18, 2016, 03:39:08 pm »
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hey! could someone please explain how you would do this question :-)
Im on a phone right now so I can't link but part i is already done.

Edit: Page 37 post 549 or something
« Last Edit: October 18, 2016, 03:42:00 pm by RuiAce »

mfjw

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Re: Mathematics Question Thread
« Reply #593 on: October 18, 2016, 03:41:43 pm »
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I'm a bit stuck on this question right now. Could someone please explain how to do Q4g and Q4h?

RuiAce

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Re: Mathematics Question Thread
« Reply #594 on: October 18, 2016, 03:43:04 pm »
+1

I'm a bit stuck on this question right now. Could someone please explain how to do Q4g and Q4h?
The answer is the question itself. It's called a trick question; it is already answered for you

jakesilove

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Re: Mathematics Question Thread
« Reply #595 on: October 18, 2016, 03:43:24 pm »
+1
I'm a bit stuck on this question right now. Could someone please explain how to do Q4g and Q4h?

Remember that



So,



I'll let you try h)
ATAR: 99.80

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RuiAce

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Re: Mathematics Question Thread
« Reply #596 on: October 18, 2016, 03:46:34 pm »
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Remember that



So,



I'll let you try h)
I nearly walked into that.

Jake, that index was already positive

jakesilove

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Re: Mathematics Question Thread
« Reply #597 on: October 18, 2016, 03:49:18 pm »
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I nearly walked into that.

Jake, that index was already positive

I know it looks positive, but I assumed the picture was just bad quality. Surely they wouldn't give an already-positive indice in numerous questions, as the image appears.
ATAR: 99.80

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Modern History: 94
English Advanced: 95
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Mathematics Extension 1: 98

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RuiAce

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Re: Mathematics Question Thread
« Reply #598 on: October 18, 2016, 03:50:38 pm »
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I know it looks positive, but I assumed the picture was just bad quality. Surely they wouldn't give an already-positive indice in numerous questions, as the image appears.
Yeah it makes sense because there was a "space" there. Oh well.

jakesilove

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Re: Mathematics Question Thread
« Reply #599 on: October 18, 2016, 03:51:52 pm »
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Yeah it makes sense because there was a "space" there. Oh well.

Either way, questioner get's a comprehensive response!
ATAR: 99.80

Mathematics Extension 2: 93
Physics: 93
Chemistry: 93
Modern History: 94
English Advanced: 95
Mathematics: 96
Mathematics Extension 1: 98

Studying a combined Advanced Science/Law degree at UNSW