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C1 Relationships between roots if quadratic questions

Question: form a quadratic equation with roots which exceed by 2 the roots of the quadratric equation 3x2(p4)x(2p+1)=0 3x^2 -(p-4)x-(2p+1)=0
My attempt:
for the given equation the sum of roots: (p4)3 \frac{(p-4)}{3}
products of roots: (2p+1)3 - \frac{(2p+1)}{3}

for the required equation its roots are 2 more than the roots of the given equation thus the roots are (α+1) (\alpha +1) and (β+1) (\beta+1)
let this be (x +1 ) and (y +1)
thus the sum of the roots wil be: (p4)3+2=(p+2)3 \frac{(p-4)}{3} +2 = \frac{(p+2)}{3}
and the products is (x+1)(y+1) = xy+x+y+1 xy+x+y+1 = (p+2)3 \frac{-(p+2)}{3}

the required equation i got is 3x2(p+2)x(p+2)=0 3x^2-(p+2)x - (p+2) = 0
but the answer in the text book is 3y2(p+8)y+3=0 3y^2 -(p+8)y +3 = 0

please tell me where i went wrong thank you
Original post by bigmansouf
please tell me where i went wrong thank you


You've only increased the roots by "1".

"roots which exceed by 2 the roots of the quadratric" means each root of the new equation is 2 higher than the corresponding root of the original equation.
I.e if roots were 2,8, then they become 4,10.
Reply 2
Original post by ghostwalker
You've only increased the roots by "1".

"roots which exceed by 2 the roots of the quadratric" means each root of the new equation is 2 higher than the corresponding root of the original equation.
I.e if roots were 2,8, then they become 4,10.

thank you very much
Original post by bigmansouf
thank you very much


What exam board are you on?? I'm on AQA btw
Reply 4
Original post by TheYearNiner
What exam board are you on?? I'm on AQA btw


edexcel but im using bostock and chandler book
Original post by bigmansouf
edexcel but im using bostock and chandler book


Yeah I was wondering why I haven't been taught that. So how are you finding year 12 1 month in man?
Reply 6
Original post by TheYearNiner
Yeah I was wondering why I haven't been taught that. So how are you finding year 12 1 month in man?


im not in yr 12 im self studying
Original post by bigmansouf
im not in yr 12 im self studying

OH right, so how old are you at the moment?
Reply 8
old
Reply 9
Original post by bigmansouf
im not in yr 12 im self studying

I'm also self-studying btw and I'm offering Mathematics, Chemistry and Physics for my International Advanced Levels in the Edexcel board. I will be taking the exam for IAS in the May/June 2017.
Original post by Rashina
I'm also self-studying btw and I'm offering Mathematics, Chemistry and Physics for my International Advanced Levels in the Edexcel board. I will be taking the exam for IAS in the May/June 2017.

what degree do u want to do?

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