Tính A=1/2 +1/3 +1/4+....+1/2008+1/2009

To find the sum of the series A, we can use the formula for the sum of an infinite geometric series:

S = a / (1 - r)

where S is the sum of the series, a is the first term, and r is the common ratio.

In this case, the first term a is 1/2 and the common ratio r is 1/2.

S = (1/2) / (1 - 1/2)
S = (1/2) / (1/2)
S = 1

Therefore, the sum of the series A is 1.