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If the surn of first n terms of an A.P is given by Sn = 3m2 + 5n, find the nth term ofthe AP |
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Answer» Sn=3n^2+5nTO FIND:nth termwe have to find value of a&d i.efirst term &common difference put n=1S1=3(1)^2+5(1)s1=3+5s1=8putn=2s2=3(2)^2+5(2)s2=12+10s2=22now,a=t1=s1a=t1=8t2=s2-s1=22-8t2=14a=8tn=8+(n-1)14....(substituting value)tn=5+14n-14tn=14n-11As a resultthe nth term is 14n-11 |
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