Question

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

neu tong duoi day keo dai mai mai thi ket qua bang bao nhieu

Answer 1

Đặt \(S=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+....\)

Khi đó: \(2S=2\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+....\right)\)

                    \(=1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+....\)

                  \(=1+\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+....\right)\)

                   \(=1+S\)

Hay là: \(2S=1+S\)

=> \(2S-S=1\)

=> \(S=1\)

Answer 2

giup minh voi

Answer 3

1111111212222222

Answer 4

cach lam co ban a

Answer 5

     S=1/2+1/4+1/8+1/16+1/32+...+1/2n

=>2S=1+1/2+1/4+1/8+1/16+...+1/n

=>2S-S=(1+1/2+1/4+...+1/n)-(1/2+1/4+...+1/2n)

=>S=1+1/n-1/2n

=>S=(2n+1)/2n

Answer 6

cảm ơn