Question

1/2+1/4+1/8+1/16+1/32+1/64...+1/2048

 

 

Answer 1

Đặt : \(A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+......+\frac{1}{2048}\)

\(2A=1+\frac{1}{2}+\frac{1}{4}+.......+\frac{1}{1024}\)

\(2A-A=1-\frac{1}{2048}\)

\(A=\frac{2047}{2048}\)

Good

Answer 2

S=1/2 +1/4+...+1/2048+1/2048-1/2048

S=1/2+1/4+...+1/1024+1/1024-1/2048

...

S=1-1/2048

S=2047/2048

Answer 3

2047/2048