Maths year 11

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Four things that unis think matter more than league tables 08-12-2016
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    (Original post by TSRPAV)
    ...
    God forbid your notation. What the hell is \frac{dy}{dx}(\frac{1}{cosx}) .dx even supposed to mean? Where's the y? Just no.
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    (Original post by B_9710)
    Ok, this is the easiest way but we will try another.
    Find  \displaystyle \int \text{cosec } x \ dx using the substitution  t=\tan (\frac{1}{2}x) .
    You're slowly turning a Y10 thread into a Y13 one.
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    (Original post by RDKGames)
    You're slowly turning a Y10 thread into a Y13 one.
    Fine. I will delete my posts. You as well though, you posted an FP4 question yesterday.
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    (Original post by B_9710)
    Fine. I will delete my posts. You as well though, you posted an FP4 question yesterday.
    You didn't have to delete them; just stop posting more, there are other threads where challenging problems can be discussed.
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    (Original post by RDKGames)
    You didn't have to delete them; just stop posting more, there are other threads where challenging problems can be discussed.
    So then? :/

    This was so Challenging.


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    (Original post by RDKGames)
    God forbid your notation. What the hell is \frac{dy}{dx}(\frac{1}{cosx}) .dx even supposed to mean? Where's the y? Just no.
    yeah sorry i always just write dy/dx but to make it clear what i was doing i wrote d(1/cosx)/dx but i always write dy out of habbit cos im lazy and prefer just doing dy/dx
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    (Original post by z_o_e)
    So then? :/

    This was so Challenging.


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    Likewise with the bottom row. It wouldn't make sense for 15x-6 to be 9x because 6 is not a multiple of x.

    Think of it this way:
    15x-6x would be 9x because you can always factor out an x from both 15 and 6, leaving you with x(15-6) where you can just take 6 away from 15 as they are not multiples of x anymore, thus leaving you with 9x.
    For 15x-6, you cannot factor out any x's because one has it and one doesn't so it wouldn't make sense.

    This is really basic, you'll get used to this pretty fast.
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    (Original post by RDKGames)
    Likewise with the bottom row. It wouldn't make sense for 15x-6 to be 9x because 6 is not a multiple of x.

    Think of it this way:
    15x-6x would be 9x because you can always factor out an x from both 15 and 6, leaving you with x(15-6) where you can just take 6 away from 15 as they are not multiples of x anymore, thus leaving you with 9x.
    For 15x-6, you cannot factor out any x's because one has it and one doesn't so it wouldn't make sense.

    This is really basic, you'll get used to this pretty fast.
    This was the last question of this past paper and can you give a few examples on these type of questions after we've found the answer to this xx

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    (Original post by TSRPAV)
    yeah sorry i always just write dy/dx but to make it clear what i was doing i wrote d(1/cosx)/dx but i always write dy out of habbit cos im lazy and prefer just doing dy/dx
    y would need to be defined in order to use dy, but I'll let you off the hook. :P
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    So is the 9x correct?



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    (Original post by z_o_e)
    This was the last question of this past paper and can you give a few examples on these type of questions after we've found the answer to this xx

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    I'll give you some quadratics to work with, sure.

    It's 15x-6, doesn't get any simpler than that.
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    (Original post by RDKGames)
    I'll give you some quadratics to work with, sure.

    It's 15x-6, doesn't get any simpler than that.
    What's the next step

    I found this the hardest! Feel like giving up on this question.

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    (Original post by z_o_e)
    What's the next step

    I found this the hardest! Feel like giving up on this question.

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    No problem, its only a matter of multiplying out the brackets and adding. Here's the full solution to show you what they want:
    Name:  ImageUploadedByStudent Room1470509966.011648.jpg
Views: 28
Size:  155.4 KB


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    (Original post by RDKGames)
    No problem, its only a matter of multiplying out the brackets and adding. Here's the full solution to show you what they want:
    Name:  ImageUploadedByStudent Room1470509966.011648.jpg
Views: 28
Size:  155.4 KB


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    Thank you )

    Can you give me a few questions to work on as you might be able to tell from the questions what part I'm weak on


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    (Original post by z_o_e)
    Thank you )

    Can you give me a few questions to work on as you might be able to tell from the questions what part I'm weak on


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    I think you're pretty good with the angles at this point, I only see that you can improve perhaps on volumes of shapes and expanding brackets. Let's do a similar one just slightly easier as not all sides are in terms of x:
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    (Original post by RDKGames)
    I think you're pretty good with the angles at this point, I only see that you can improve perhaps on volumes of shapes and expanding brackets. Let's do a similar one just slightly easier as not all sides are in terms of x:
    Name:  Q26.PNG
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    so first I split the shape in two.



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    (Original post by z_o_e)
    so first I split the shape in two.



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    Yep, now label the sides of each rectangle.
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    (Original post by RDKGames)
    Yep, now label the sides of each rectangle.
    But I don't know the sides

    Like 15 - X will give me the bottom side but I don't know how to find X.



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    (Original post by z_o_e)
    But I don't know the sides

    Like 15 - X will give me the bottom side but I don't know how to find X.



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    15-x will indeed give you the bottom side, use it. Don't worry about x as we will find it at the very end. This question firstly wants us to get the area of the whole shape in terms of x before we solve for it.
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    (Original post by RDKGames)
    15-x will indeed give you the bottom side, use it. Don't worry about x as we will find it at the very end. This question firstly wants us to get the area of the whole shape in terms of x before we solve for it.
    How's this?


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