if the sum of first m tern of an A.P is am^2+bm, find its common diffe

1.	if the sum of first m tern of an A.P is am^2+bm, find its common difference
Answer» Taking m = 1, we have S1 = T1 =\xa0a + bTaking m = 2, we have S2 = T1 +\xa0T2 =\xa04a + 2bTaking m = 3, we have S3 = T1 +\xa0T2\xa0+ T3\xa0=\xa09a + 3bTherefore, T2 = S2 - S1 = 4a + 2b - a - b = 3a + bAlso, T3 = S3 - S2 = 9a + 3b - 4a - 2b = 6a + bTherefore, Common difference = 6a + b - 3a - b = 3a\xa0

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