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March 30, 2024, 02:07:09 am

Author Topic: Mathematics Question Thread  (Read 1297263 times)  Share 

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julzzz

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Re: Mathematics Question Thread
« Reply #510 on: October 15, 2016, 03:33:52 pm »
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I have to differentiate: 3x/√3x-4+√3x-4

I end up getting (9√2)/8 but the answer is (3√2)8

I'm so close yet so far... help!

RuiAce

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Re: Mathematics Question Thread
« Reply #511 on: October 15, 2016, 03:40:08 pm »
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I have to differentiate: 3x/√3x-4+√3x-4

I end up getting (9√2)/8 but the answer is (3√2)8

I'm so close yet so far... help!


julzzz

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Re: Mathematics Question Thread
« Reply #512 on: October 15, 2016, 03:43:27 pm »
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Oh I'm so sorry, I meant to add that f'(x) = 2

jakesilove

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Re: Mathematics Question Thread
« Reply #513 on: October 15, 2016, 03:50:24 pm »
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Oh I'm so sorry, I meant to add that f'(x) = 2

Using Rui's answer, and setting it equal to two, you find that x is a complex number. Potentially you haven't fully described the question properly; can you just post a screenshot?
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RuiAce

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Re: Mathematics Question Thread
« Reply #514 on: October 15, 2016, 03:52:04 pm »
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Oh I'm so sorry, I meant to add that f'(x) = 2
Doesn't mean anything because that has no (real) solutions.

Are you sure you haven't differentiated already and were trying to say that what you gave us WAS the derivative?

jakesilove

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Re: Mathematics Question Thread
« Reply #515 on: October 15, 2016, 03:53:42 pm »
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Doesn't mean anything because that has no (real) solutions.

Are you sure you haven't differentiated already and were trying to say that what you gave us WAS the derivative?

Nup, that still produces a complex solution
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RuiAce

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Re: Mathematics Question Thread
« Reply #516 on: October 15, 2016, 03:55:14 pm »
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Nup, that still produces a complex solution
I have no clue either then. We need the actual question.

julzzz

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Re: Mathematics Question Thread
« Reply #517 on: October 15, 2016, 04:07:51 pm »
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I have no clue either then. We need the actual question.

Here you go :)

Sorry if I stuffed up the question

RuiAce

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Re: Mathematics Question Thread
« Reply #518 on: October 15, 2016, 04:10:52 pm »
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Here you go :)

Sorry if I stuffed up the question


julzzz

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Re: Mathematics Question Thread
« Reply #519 on: October 15, 2016, 04:17:07 pm »
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I understand how to get f'(x) but don't know how to get f''(x) which will let me finish the question as I can sub in 2 then.

RuiAce

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Re: Mathematics Question Thread
« Reply #520 on: October 15, 2016, 04:21:14 pm »
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I understand how to get f'(x) but don't know how to get f''(x) which will let me finish the question as I can sub in 2 then.

« Last Edit: October 15, 2016, 04:40:32 pm by RuiAce »

RuiAce

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Re: Mathematics Question Thread
« Reply #521 on: October 15, 2016, 04:30:18 pm »
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Sorry, your post came up with random symbols thrown into it making it very difficult to read...
If you're in an app, go into web view. LaTeX does not get produced on the app; you need a proper web browser.

Otherwise I'm not sure at all what the problem is and you will need to provide sufficient evidence including screenshots for technical help.

julzzz

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Re: Mathematics Question Thread
« Reply #522 on: October 15, 2016, 04:38:44 pm »
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Sorry for being so naggy, but where did the 2 go at the end of the first differentiation?

RuiAce

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Re: Mathematics Question Thread
« Reply #523 on: October 15, 2016, 04:40:51 pm »
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Sorry for being so naggy, but where did the 2 go at the end of the first differentiation?
Fixed, my bad on the accident there

julzzz

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Re: Mathematics Question Thread
« Reply #524 on: October 15, 2016, 04:56:06 pm »
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Fixed, my bad on the accident there

Cheers
Really appreciate all your help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!