Question

If the sum of the first n terms of arithmetic progression is given by an=3n²-n,then the 25th term of the arithmetic progression is

Answer 1

Step-by-step explanation:

sn=3n^2-n

first term (a1)=s1=3(1)^2-1=2

secound term (a2)=s2=3(2)^2-2=10

common difference (d)=a2-a1=10-2=8

s2=a1+a2=10+2=12

an=a+(n-1)d

a25=2+(25-1)×8

=2+24×8

=2+192

=194