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March 29, 2024, 10:06:15 am

Author Topic: 3U Maths Question Thread  (Read 1230422 times)  Share 

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RuiAce

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Re: 3U Maths Question Thread
« Reply #765 on: October 13, 2016, 10:19:07 pm »
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thank you for you help
I got confused on how to multiply out the denominators and use the quadratic formula to find solutions. How do you do this?  :o



anotherworld2b

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Re: 3U Maths Question Thread
« Reply #766 on: October 13, 2016, 10:54:25 pm »
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I was wondering why is it 7x/5000? I got 14x/5000 for some reason?




RuiAce

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Re: 3U Maths Question Thread
« Reply #767 on: October 13, 2016, 11:01:31 pm »
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I copied Jake's working wrong. That was meant to be 7x/2500 which is equivalent to 14x/5000

anotherworld2b

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Re: 3U Maths Question Thread
« Reply #768 on: October 13, 2016, 11:11:35 pm »
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Is it supposed to be like this?  ???

jakesilove

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Re: 3U Maths Question Thread
« Reply #769 on: October 14, 2016, 10:35:50 am »
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Is it supposed to be like this?  ???

Looks right!
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kiwiberry

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Re: 3U Maths Question Thread
« Reply #770 on: October 15, 2016, 01:18:08 pm »
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how do you integrate this :-\


« Last Edit: October 15, 2016, 01:29:58 pm by kiwiberry »
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RuiAce

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Re: 3U Maths Question Thread
« Reply #771 on: October 15, 2016, 01:20:56 pm »
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kiwiberry

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Re: 3U Maths Question Thread
« Reply #772 on: October 15, 2016, 01:30:38 pm »
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ohh thank you!! could you please do this one as well :)
« Last Edit: October 15, 2016, 09:38:11 pm by kiwiberry »
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jakesilove

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Re: 3U Maths Question Thread
« Reply #773 on: October 15, 2016, 01:36:28 pm »
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ohh thank you!! could you please do this one as well :)


Hey! I would expand the the denominator out, and then use completing the square to get something that looks like a^2-(x-c)^2 in the square root. From there, you can easily let u=x-c so that you can integrate using inverse sin/cos! Show us some working out, and if you still can't get it we'd be happy to write up a solution.
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kiwiberry

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Re: 3U Maths Question Thread
« Reply #774 on: October 15, 2016, 09:39:43 pm »
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Hey! I would expand the the denominator out, and then use completing the square to get something that looks like a^2-(x-c)^2 in the square root. From there, you can easily let u=x-c so that you can integrate using inverse sin/cos! Show us some working out, and if you still can't get it we'd be happy to write up a solution.

i think i got it! :D thanks
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RuiAce

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Re: 3U Maths Question Thread
« Reply #775 on: October 15, 2016, 09:46:26 pm »
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jamgoesbam

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Re: 3U Maths Question Thread
« Reply #776 on: October 17, 2016, 08:39:53 am »
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Hi there,
I was just wondering how did they get the answer for this question?? Could someone please explain? Thanks! :)

RuiAce

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Re: 3U Maths Question Thread
« Reply #777 on: October 17, 2016, 09:33:33 am »
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Hi there,
I was just wondering how did they get the answer for this question?? Could someone please explain? Thanks! :)
The first two parts are elementary formula work
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bethjomay

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Re: 3U Maths Question Thread
« Reply #778 on: October 18, 2016, 09:18:30 pm »
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If our working is a little dodgy (I.e made some leaps in my head) but the answer is correct can you still get full marks?
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jakesilove

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Re: 3U Maths Question Thread
« Reply #779 on: October 18, 2016, 09:26:08 pm »
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If our working is a little dodgy (I.e made some leaps in my head) but the answer is correct can you still get full marks?

You certainly can! The only exception to this is in a 'show that' question, because they'll think you're bullshitting since you know the answer, or if you get the question incorrect
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