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    can someone tell how to know if a question is about 'quadratics in disguise'.
    how do i recognize one?
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    If there is a term in x^4 then at C1 level, it's likely to be one!
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    What board are you?
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    Usually it'd be when the first term is to the power of 4, eg:
    x^{4} and the second term will be to the power of x^{2}

    Though it could work work when the first term has a power that is double to that of the second term, though I havent come across anything other than 4 before .
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    (Original post by cooldudeman)
    can someone tell how to know if a question is about 'quadratics in disguise'.
    how do i recognize one?
    You'll just have to try to recognise it. Generally speaking, if you have:

    ax^d +bx^e +c=0, such that,

    d=2e, it'll be some disguised quadratic, where you can make some substitution. Commonly, in C1, you'll find the powers to be 4 or 6, but it's not restricted to these. You may get something like:

    x + 2 \sqrt{x} +1 =0 and you'll have to notice that it can be rewritten as,

    x + 2x^{\frac{1}{2}} +1 =0 and so we have a disguised quadratic, with surds and such.
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    ok thanks for the replies
 
 
 
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