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# AS maths C1 question watch

1. (Original post by serah.exe)
That's quite alright, everyone makes mistakes
Don't patronise me
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Nice illustration in post 16 btw
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Shame it was wrong
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2. (Original post by serah.exe)
Ayy I think you're correct.
Thanks for your help people, I guess I will take it as book error and move on.
3. (Original post by Vikingninja)
I just found the minimum point and it actually only works if it is equal to or smaller than -2 or greater than 6 so yeah im wtfing now. Should ask your teacher when you next see them.
No, just when k<-2 (and when k>6), not when k=2 (in this case b^2-4ac=0 which means it only has one real root).
4. (Original post by Illiberal Liberal)
No, just when k<-2 (and when k>6), not when k=2 (in this case b^2-4ac=0 which means it only has one real root).
Oh yeah forgot the question had plural roots.
5. (Original post by serah.exe)
I think it is a book error. I remember doing the same question and it said that it had no real roots.
Attachment 461723
Thats where I match my solution and if you see the B part its totally same and they wrote it correct but they still solved it wrong. Anyways heres the full exercise in the edexcel c1 book https://gyazo.com/53e50be42dfbd25b60c49fb2147cb783
6. (Original post by serah.exe)
I think it is a book error. I remember doing the same question and it said that it had no real roots.
Attachment 461723
Why is that a book error?

No real roots simply means b^2-4ac<0 (but I assume you already know this so forgive me for coming across as condescending... ).
7. (Original post by Illiberal Liberal)
Why is that a book error?

No real roots simply means b^2-4ac<0 (but I assume you already know this so forgive me for coming across as condescending... ).
(Original post by Hamzah249)
Thats where I match my solution and if you see the B part its totally same and they wrote it correct but they still solved it wrong. Anyways heres the full exercise in the edexcel c1 book https://gyazo.com/53e50be42dfbd25b60c49fb2147cb783
thats why
8. (Original post by Hamzah249)
Q.Find the range of values of k for which the equation x^2-kx+(k+3)=0 has real roots.

So this means that b^2-4ac >= 0

But the answer in the book and solution book are both same which doesn't make sense. Can someone please solve this here so I can match my answer? Im pretty sure it's wrong in the book.
(Original post by Vikingninja)
k^2-4a(k+3)>0

Go from there.
(Original post by serah.exe)
Here you go, excuse the paint skills lmao.
Attachment 461681
(Original post by midgemeister7)
Yep, those workings do not make sense. Should be what you said.
(Original post by Illiberal Liberal)

Guys you will be better off to discuss maths help on problems such as this in the correct forum
http://www.thestudentroom.co.uk/forumdisplay.php?f=38.

Over there is where most of the "maths helpers" visit.
This is a subforum for discussion of specific maths exams.

If you are all of you are taking maths this year, I wish you all the best.

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