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English-help
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http://mathsathawthorn.pbworks.com/f/FP1Jun06.pdf
Could someone teach me how to start on q4?
The last time I did geometric series was in core 2 but ive forgot them:/
Is it a,ar, ar^2?
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Welshstig
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Form of a geometric series:

a + ar + ar^2

We know that the common ratio, r, is 2, so:

a + 2a + 4a.

This means that the first root is equal a, the second, 2a, and the third, 4a.
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RDKGames
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(Original post by English-help)
http://mathsathawthorn.pbworks.com/f/FP1Jun06.pdf
Could someone teach me how to start on q4?
The last time I did geometric series was in core 2 but ive forgot them:/
Is it a,ar, ar^2?
Yes the roots would be a, 2a, 2^2a such that a>0 in order for them to be positive.

Then just equate \displaystyle \sum \alpha \beta = 56 from your knowledge of roots of cubic polynomials, and solve for a.
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English-help
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(Original post by RDKGames)
Yes the roots would be a, 2a, 2^2a such that a>0 in order for them to be positive.

Then just equate \displaystyle \sum \alpha \beta = 56 from your knowledge of roots of cubic polynomials, and solve for a.
Okayy good
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