Question

Find the sum of the geometric series:
1+ sqrt6+ 6+...+7776

Answer 1

(Sqrt[6])^n-1

Answer 2

(Sqrt[6])^n-1=7776

n=11

Answer 3

use the formula

Answer 4

1- y^n+1
----------
1 - y

Answer 5

1- Sqrt[6]^12
-------------
1- sqrt[6 ]