Answer:
(a)= option 3
(b)= option 3
Step-by-step explanation:
(A) It is given that a sequence is defined by the recursive function and
Now, substituting the value of n=2 in above equation,
Again putting n=3,
Putting n=4,
Putting n=5,
Putting n=6,
Putting n=7,
Hence, option 3 is correct.
(B) The given sequence is :
5, -10, 20, -40, 80.....
Since, the given sequence is GP, therefore
and r=-2
The nth term is given by:
For fifteenth term, put n=15 in above equation, we get
=
=
Hence, the fifteenth term is 81920.
Option 3 is correct.