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The nth term of an arithmetic sequence is 3_5n.Write first term and common difference? |
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Answer» Step-by-step explanation: UM of first n terms of an arithmetic sequence is 3n 2 +n. Let a
denotes first TERM of the sequence, a 2
denotes second term of the sequence, d denotes common difference of the sequence, S n
denotes sum of first n terms of the sequence. S n
=3n 2 +n S 1
=a 1
=3(1) 2 +1=4 S 2
=a 1
+a 2
=3(2) 2 +2=14 ∴a 1
+a 2
=14 ∴a 1
+a 1
+d=14 ∴2a 1
+d=14 ∴2(4)+d=14 ∴d=6 First term of the sequence is 4 and common difference is 6. |
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