Q3 of 167 Page 20

If the sum of n terms of an AP is , then write its nth term.

Here, S_n=2n²+3n

So, S₁=2+3=5=t₁

And S₂=2×2²+3×2

=8+6=14

So, t₂=S₂-S₁

=14-5

Now, common difference of A.P. is given by

d=t₂-t₁

=9-5

So, n^th term of A.P. is

a_n=t₁+(n-1)d

=5+(n-1)4

=5+4n-4

=4n+1

Write the common difference of an A.P. whose nth term is xn + y.

If log 2, and are in A.P., write the value of x.

If the sum of n terms of two arithmetic progressions are in the ratio 2n + 5 : 3n + 4, then write the ratio of their mth terms.