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# OCR Maths C2 Question Tweet

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1. OCR Maths C2 Question
Ok very simple, please look at the picture attached. I just dont get the beginning of part iv. Why is the relevant value (3-root5)/2 and not (3+root5)/2?
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2. Re: OCR Maths C2 Question
The question states that the progression is convergent. Therefore, the common ratio for the sequence is a decimal. As only (3-root5)/2 fits the category, you need to use that solution
3. Re: OCR Maths C2 Question
(Original post by z95)
The question states that the progression is convergent. Therefore, the common ratio for the sequence is a decimal. As only (3-root5)/2 fits the category, you need to use that solution
(3+root5)/2 is also a decimal though

4. Re: OCR Maths C2 Question
(Original post by schoolrun)
(3+root5)/2 is also a decimal though

Sorry what I meant was that r is between -1 and 1. Sorry for not being clear an thanks for the rep
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