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March 29, 2024, 06:44:59 am

Author Topic: Mathematics Question Thread  (Read 1296861 times)  Share 

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conic curve

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Re: Mathematics Question Thread
« Reply #375 on: September 13, 2016, 05:53:50 pm »
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RuiAce

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Mathematics Question Thread
« Reply #376 on: September 13, 2016, 06:12:11 pm »
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They interesect at the origin
Not the point.

Here I might have a favouritism towards the graphs I suggested (Jake picked the most coincidental) but read the above posts 5 times.

Where f(x) is INCREASING, f'(x) is ABOVE THE X-AXIS etc.

Know what you're comparing. To know what you're comparing, read all of the above posts 5 times. Read and compare simultaneously
« Last Edit: September 13, 2016, 06:15:20 pm by RuiAce »

conic curve

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Re: Mathematics Question Thread
« Reply #377 on: September 13, 2016, 06:24:02 pm »
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Not the point.

Here I might have a favouritism towards the graphs I suggested (Jake picked the most coincidental) but read the above posts 5 times.

Where f(x) is INCREASING, f'(x) is ABOVE THE X-AXIS etc.

Know what you're comparing. To know what you're comparing, read all of the above posts 5 times. Read and compare simultaneously

So imagine f'(x) was the cubic in the image I have attached above

Is it the fact that f(x), f'(x) and f''(x) are all monotonic increasing

Also for this question below, for 16 and 17 I know how to do it in my head but am not sure how to geometrically prove it

Also for 18, the answer is 6,6 but I got 3


RuiAce

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Mathematics Question Thread
« Reply #378 on: September 13, 2016, 06:29:11 pm »
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So imagine f'(x) was the cubic in the image I have attached above

Is it the fact that f(x), f'(x) and f''(x) are all monotonic increasing

Also for this question below, for 16 and 17 I know how to do it in my head but am not sure how to geometrically prove it

Also for 18, the answer is 6,6 but I got 3

(Image removed from quote.)
For the sake of this question, STOP considering f"(x).

Like I said, WHEN f(x) is INCREASING, the DERIVATIVE f'(x) is POSITIVE.

ALL I want you to note is when f(x) is increasing/decreasing/stationary that f'(x) is above/below/intersecting the x-axis respectively. I think you do not understand what our explanations meant.

For Q18, the correct answer should technically be 6,3. 6,6 is not right in my opinion as there's double counting.
« Last Edit: September 13, 2016, 06:30:43 pm by RuiAce »

conic curve

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Re: Mathematics Question Thread
« Reply #379 on: September 13, 2016, 06:39:02 pm »
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To prevent confusion I decided to redo the question given the information you and Jake gave me

If it is above the x axis, it is monotonic increasing and if it is below the x axis, it is monotonic decreasing


RuiAce

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Re: Mathematics Question Thread
« Reply #380 on: September 13, 2016, 06:57:49 pm »
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To prevent confusion I decided to redo the question given the information you and Jake gave me

If it is above the x axis, it is monotonic increasing and if it is below the x axis, it is monotonic decreasing

(Image removed from quote.)
How you labelled your +,s and -'s are correct but the graph you ended up drawing makes no sense.


conic curve

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Re: Mathematics Question Thread
« Reply #381 on: September 13, 2016, 09:32:53 pm »
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WHat is the answer to this

RuiAce

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Re: Mathematics Question Thread
« Reply #382 on: September 13, 2016, 09:38:43 pm »
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WHat is the answer to this
Well what was your attempt?

conic curve

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Re: Mathematics Question Thread
« Reply #383 on: September 13, 2016, 10:04:59 pm »
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Well what was your attempt?

I found the domain first and got x is not equal to 4 and subbed back in to the original equation in order to find the range but then I get 1/0 as the range (which is infinity which is all y)

Am I right?

RuiAce

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Re: Mathematics Question Thread
« Reply #384 on: September 13, 2016, 10:06:36 pm »
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I found the domain first and got x is not equal to 4 and subbed back in to the original equation in order to find the range but then I get 1/0 as the range (which is infinity which is all y)

Am I right?
That's only a part of the answer.

Anything under a square root also has to be positive.
« Last Edit: September 13, 2016, 10:45:11 pm by RuiAce »

kaufoou

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Re: Mathematics Question Thread
« Reply #385 on: September 17, 2016, 08:52:00 am »
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Hey! So I was wondering if it is worth buying a Mathomat or Math-Aid to take into the exam? (btw they're permitted by BOSTES)

RuiAce

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Re: Mathematics Question Thread
« Reply #386 on: September 17, 2016, 08:59:30 am »
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Hey! So I was wondering if it is worth buying a Mathomat or Math-Aid to take into the exam? (btw they're permitted by BOSTES)
They are most certainly permitted and I bought one in for each of my maths exams.

But their value isn't that great. They just help you draw a really neat sine curve and circles and what not. I'm fairly positive BOSTES is lenient on certain diagrams being decent enough.

If you spend too much time fussing over graphing like me, however, then you may as well because they're not "expensive" either. The math-aid is more powerful than the mathomat, but the latter comes with a protractor

olivercutbill

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Re: Mathematics Question Thread
« Reply #387 on: September 17, 2016, 04:00:42 pm »
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How am I supposed to do vi)

Answer for v) is (40)^1/2

Thanks
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RuiAce

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Re: Mathematics Question Thread
« Reply #388 on: September 17, 2016, 04:31:33 pm »
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How am I supposed to do vi)

Answer for v) is (40)^1/2

Thanks


lha

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Re: Mathematics Question Thread
« Reply #389 on: September 19, 2016, 06:50:33 pm »
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How many past papers shpuld we complete before hsc?