Question

if a1 =A2=2,an=an-1-1n>2 then a5 is ​

Answer 1

Answer :

a(5) = -1

Solution :

• Given : a(1)= a(2) = 2 , a(n) = a(n-1) - 1 , n>2

• To find : a(5) = ?

We have ;

• a(1) = 2

• a(2) = 2

Also ,

a(n) = a(n-1) - 1 , n > 2

Thus ,

=> a(3) = a(3-1) - 1

=> a(3) = a(2) - 1

=> a(3) = 2 - 1

=> a(3) = 1

Now ,

=> a(4) = a(4-1) - 1

=> a(4) = a(3) - 1

=> a(4) = 1 - 1

=> a(4) = 0

Also ,

=> a(5) = a(5-1) - 1

=> a(5) = a(4) - 1

=> a(5) = 0 - 1

=> a(5) = -1

Hence , a(5) = -1 .