Question

If an=n2+1 then s2 will be

Answer 1

Answer:

S(2) = 7

Solution:

• Given : a(n) = n² + 1
• To find : S(2) = ?

We know that ;

a(n) denotes the nth term of a sequence and S(n) denotes the sum of n terms of the sequence .

In general , S(n) = a(1) + a(2) + a(3) +...+a(n).

We have ;

a(n) = n² + 1

Thus,

First term , a(1) = 1² + 1 = 1 + 1 = 2

Also,

Second term , a(2) = 2² + 1 = 4 + 1 = 5

Now,

=> S(2) = a(1) + a(2)

=> S(2) = 2 + 5

=> S(2) = 7

Hence,

Required answer is 7 .