Simplifying binomial expansions Edexcel

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velaris08
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Just wondering if anyone had any advice as to what counts as "simplified"? Just did a binomials Q where everything had to be halved at the end, so I just took my expansion and halved it. Markscheme looks like it awards the last mark for showing 1/2 (expansion). I showed 1/2(1-3/4 x)^-1/2 i.e. what had been expanded, but not the explicit expansion. Made a mental note to show that next time - but can anyone tell me how to tell what the best simplified form is? Not even neccessarily for binomials but just in general - when it comes to everything having to be halved/quartered etc etc - should I just leave it like that instead?
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mqb2766
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(Original post by velaris08)
Just wondering if anyone had any advice as to what counts as "simplified"? Just did a binomials Q where everything had to be halved at the end, so I just took my expansion and halved it. Markscheme looks like it awards the last mark for showing 1/2 (expansion). I showed 1/2(1-3/4 x)^-1/2 i.e. what had been expanded, but not the explicit expansion. Made a mental note to show that next time - but can anyone tell me how to tell what the best simplified form is? Not even neccessarily for binomials but just in general - when it comes to everything having to be halved/quartered etc etc - should I just leave it like that instead?
Can you upload the question, the markscheme and what you did. It does help.
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velaris08
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(Original post by mqb2766)
Can you upload the question, the markscheme and what you did. It does help.
Sorry - here.
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mqb2766
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(Original post by velaris08)
Sorry - here.
tbh I would have put it in the form you did. Each term is simplified and its what is given as the solution at the top of the second page. Cant give a definitive answer however, so maybe just keep an eye out in case you come across this again.

For instance in
https://naikermaths.com/wp-content/u...ARK-SCHEME.pdf
they don't do a simple factorization of the final power series, which is what Id expect. So just do what you did unless explicitly asked for.
Last edited by mqb2766; 3 weeks ago
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velaris08
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(Original post by mqb2766)
tbh I would have put it in the form you did. Each term is simplified and its what is given as the solution at the top of the second page. Cant give a definitive answer however, so maybe just keep an eye out in case you come across this again.

For instance in
https://naikermaths.com/wp-content/u...ARK-SCHEME.pdf
they don't do a simple factorization of the final power series, which is what Id expect. So just do what you did unless explicitly asked for.
Thanks. I'll probably just try and slip in the intermediate fully written out version if I have time.
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