When you square a number, you chose a number and multiplying itself. If you did the square root of 25, you would get 5. However if you divided 25 by 2, you would get 12.5 which is NOT the square root.
There is no sum for this geometric series. it diverges rather than converges due to the absolute value of the common ratio (r), which is -3, being 3. for a geometric series to have a sum (to converge), the absolute value of r must be less than 1. (you find r by dividing a2/a1, a3/a2, etc.) hope this helps
