Sequence

1. Find the sum (2+1/2)^2 + (4+1/4)^2 +.......+ (2^n + 1/2^n ) .

2.. The infinite sum of a geometric sequence is 4 and the infinite sum of the cubes of its terms is equal to 192. Find the first term and the common difference.

ANS 1. 2n +4/3(4^n -1) + 1/3(1- 1/4^n)
ANS 2. a=6 , r = -1/2