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    What was the answer for factorising x4 - 81. I got (x+3)(x-3)(x2+9) I think
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    (Original post by Chittesh14)
    Did you?
    I just factorised it lol... (x-8)(x-12)



    Lol, I'm a complete imbecile. I do this for every GCSE - just my lazy personality, I finish or don't finish. I never check the paper.
    Oh, well I did anyway and got the right answer, so I guess it doesn't matter how you do it as long as you do it kinda thing
    And I don't like factorising big numbers as I know I'm likely to make a mistake - I ended up with (x-10)²< 4 which, after a little bit of trial and error, led me to the right answer.
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    (Original post by Redcoats)
    What was the answer for factorising x4 - 81. I got (x+3)(x-3)(x2+9) I think
    Same here, I liked that one
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    (Original post by NiamhM1801)
    of course you can't square root a negative number
    Blasphemy!!
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    (Original post by B_9710)
    Blasphemy!!
    Haha what? Who have I betrayed so badly?
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    (Original post by NiamhM1801)
    Oh, well I did anyway and got the right answer, so I guess it doesn't matter how you do it as long as you do it kinda thing
    And I don't like factorising big numbers as I know I'm likely to make a mistake - I ended up with (x-10)²< 4 which, after a little bit of trial and error, led me to the right answer.
    Yeah lol, it happens. I'm good with that stuff, so I don't mind. I'm just a bit of a ****, need to fix myself up before Wednesday's physics exam and Friday's Further Maths exam lol.

    (Original post by Redcoats)
    What was the answer for factorising x4 - 81. I got (x+3)(x-3)(x2+9) I think
    Yeah, it's somewhere in the mark scheme lol. Thats right.

    (Original post by NiamhM1801)
    Same here, I liked that one
    Yeah, mainly because it was just easy lol
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    It wasn't.
    There were factors of 96: -12-8 =-20
    That's the numbers you use to factorise
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    (Original post by vishantu_success)
    It wasn't.
    There were factors of 96: -12-8 =-20
    That's the numbers you use to factorise
    I realise now, I couldn't find them then - kept experimenting with 24 and 4 to no avail, obviously.
    Thanks though
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    (Original post by NiamhM1801)
    Haha what? Who have I betrayed so badly?
    You said you can't square root a negative number.
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    (Original post by Chittesh14)
    Yeah lol, it happens. I'm good with that stuff, so I don't mind. I'm just a bit of a ****, need to fix myself up before Wednesday's physics exam and Friday's Further Maths exam lol.



    Yeah, it's somewhere in the mark scheme lol. Thats right.



    Yeah, mainly because it was just easy lol
    Yeah, I've always been good at completing the square so I stuck to that rather than risking errors in factorising.

    Oh I'm a mess too don't worry, I've got chemistry on Wednesday which I'm so not ready for and it's terrifying me. I might actually revise FM a bit before Friday's exam, to make sure I truly smash it
    Good luck!
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    (Original post by B_9710)
    You said you can't square root a negative number.
    You can't, can you?
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    (Original post by NiamhM1801)
    You can't, can you?
    https://en.m.wikipedia.org/wiki/Imaginary_unit
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    (Original post by NiamhM1801)
    I realise now, I couldn't find them then - kept experimenting with 24 and 4 to no avail, obviously.
    Thanks though
    I'm not sure that's right.
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    (Original post by vishantu_success)
    I'm not sure that's right.
    It's not - that's my point.
    I couldn't find a pair of factors that worked, so chose to complete the square instead as I saw that 96 was very close to 100 and 10 was a factor of 20 so it was easy enough to do.
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    Oh alright you win, I'd rather save that stuff for September thank you very much!
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    what was the question for k=9, and what steps did you take to get there?
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    (Original post by NiamhM1801)
    Oh alright you win, I'd rather save that stuff for September thank you very much!
    A-levels? This stuff won't come up unless you plan on taking further maths.
    Good luck with your exams anyhow.
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    *writes name on paper and that is all* wellll, i'll make it up in paper 2
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    for K=9 i differentiated the equation and ended up getting (3,0) as a turning point. After substituting that in for y and x of the original equation and rearranging I came out with k= 9. It that the right method?
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    (Original post by B_9710)
    A-levels? This stuff won't come up unless you plan on taking further maths.
    Good luck with your exams anyhow.
    Yeah I am doing further - probably shouldn't as apparently I can't expand cubic brackets properly but oh well 😂😂
    Thank you. Are you sitting exams or are you beyond that?
 
 
 
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