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How is this an arithmetic sequence? (1 Viewer)
- Thread starter BlueGas
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Silly Sausage
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- 2014
Therefore an AP
Flop21
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To test for an AP, it must satisfy... T2 - T1 = T3 - T2.
ln(x^2) - ln(x) = ln(x) [we know ln x - ln y = ln (x/y) and have used that here].
Do same for T3 - T2, and you'll get the same answer ln(x), therefore it's an AP and that's your AP difference.
In this question you would test for AP, GP and if it was a GP, a limiting sum as well (to see which answer it is).
To test for a GP, it must satisfy... T2 / T1 = T3 / T2.
A GP has a limiting sum if |r| < 1
ln(x^2) - ln(x) = ln(x) [we know ln x - ln y = ln (x/y) and have used that here].
Do same for T3 - T2, and you'll get the same answer ln(x), therefore it's an AP and that's your AP difference.
In this question you would test for AP, GP and if it was a GP, a limiting sum as well (to see which answer it is).
To test for a GP, it must satisfy... T2 / T1 = T3 / T2.
A GP has a limiting sum if |r| < 1