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    This may seem like a really obvious question but I can't seem to work out how to do this integration:

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    I've tried substitution but it's only made the whole thing more complicated. Any ideas?
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    Try  \displaystyle x= \frac{\sqrt 5}{2} \sinh t
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    It looks like there's been an error whilst giving you this question, it's quite tedious and annoying. There's the hyperbolic trig sub as the above user has pointed out or x \mapsto \frac{\sqrt{5}\tan x}{2} which gets you \frac{5}{2} \int \sec^3 x \, \mathrm{d}x where a standard reduction formulae gets you where you want to go.
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    (Original post by B_9710)
    Try  \displaystyle x= \frac{\sqrt 5}{2} \sinh t
    thank you! i don't think i've been taught trigonometric substitution, yet this is a question in the AQA fp2 text book so i'm guessing i have to learn it.
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    (Original post by XOR_)
    How about differentiating y=(4x^2+5)^3/2; therefore dy/dx = (8x)(3/2)(4x^2+5)^(1/2)?
    Nopes.
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    (Original post by Zacken)
    Nopes.
    Ah kay
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    is this supposed to be in the AQA FP2 specification? i have no recollection of having learnt it! :-/
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    (Original post by tanyapotter)
    is this supposed to be in the AQA FP2 specification? i have no recollection of having learnt it! :-/
    Have you learnt about hyperbolic functions?
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    (Original post by Zacken)
    Have you learnt about hyperbolic functions?
    yes. i know up to integrals which integrate to inverse hyperbolic functions but i'm pretty sure i don't know how to substitute trig functions in to integrate
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    (Original post by tanyapotter)
    thank you! i don't think i've been taught trigonometric substitution, yet this is a question in the AQA fp2 text book so i'm guessing i have to learn it.
    Well there is not a specific section on integration using hyperbolic functions - you have simply been made aware of the hyperbolic functions in FP2 - tools which can be used for integration.
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    (Original post by tanyapotter)
    yes. i know up to integrals which integrate to inverse hyperbolic functions but i'm pretty sure i don't know how to substitute trig functions in to integrate
    I'm fairly sure you should... it's on Edexcel FP2 that's for sure. Do you have a link to the FP2 AQA specification?
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    (Original post by Zacken)
    I'm fairly sure you should... it's on Edexcel FP2 that's for sure. Do you have a link to the FP2 AQA specification?
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    this screenshot shows everything that comes under inverse trig and hyperbolics and i've covered all of this content
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    (Original post by Zacken)
    I'm fairly sure you should... it's on Edexcel FP2 that's for sure. Do you have a link to the FP2 AQA specification?
    Wait wut? You sure that's not FP3 Edexcel?
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    (Original post by Student403)
    Wait wut? You sure that's not FP3 Edexcel?
    :facepalm: Yeah, that's what I meant. I mashed all my learning of C1-4 together and mashed FP2-3 together so I don't know what's in one and not the other. Thanks.
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    (Original post by Zacken)
    :facepalm: Yeah, that's what I meant. I mashed all my learning of C1-4 together and mashed FP2-3 together so I don't know what's in one and not the other. Thanks.
    Typical you learning so fast :3

    All good


    (Original post by tanyapotter)
    x
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    (Original post by Student403)
    Typical you learning so fast :3

    All good




    :wavey:
    that's such a relief. i've spent so long trying to work it out! thanks
 
 
 
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