Question

tính nhanh

A=1/2+1/2^2+1/2^3+...+1/2^10

Answer 1

a=1/2+1/2^2+.........+1/2^10

2a=1+1/2+1/2^2+........+1/2^9

2a-a=1-2^10

=1023/1024

Answer 2

2A=2*(1/2+1/2^2+....+1/2^10)

2A=1+1/2+1/2^2+....+1/2^9

2A - A =A=1 - 1/2^10

Answer 3

Đặt S = 2¹ + 2² + 2³ + ... + 2¹⁰ 

=> 2S = 2² + 2³ + ... + 2¹⁰ + 2¹¹

=> ( 2S  - S ) =  (2² + 2³ + ... + 2¹⁰ + 2¹¹ )- (2¹ + 2² + 2³ + ... + 2¹⁰ )

=> S = 2¹¹ - 2¹

Tiếp theo làm gì ta

Answer 4

a= 1/2 + 1/2^2+......... +1/2^10

2a=1 + 1/2 + 1/2^2 +........+1/2 ^9

2a - a = 1 -2^10

=1023 / 1024

Answer 5

2A=\(1+\frac{1}{2}+\frac{1}{2^2}+...............+\frac{1}{2^9}\)

2A-A=\(1-\frac{1}{2^{10}}\)

A=\(\frac{1024}{1024}-\frac{1}{1024}\)

A=\(\frac{1023}{1024}\)

Answer 6

A=1/2+1/2^2+1/2^3+...+1/2^10

A=1/2+1//4+...+1/2048

2A=2(1/2+1/4+...+1/2048)

2A=1+1/2+...+1/512

A=91+1/2+...+1/512)-(1/2+1/4+...+1/2048)

A=1-1/2048

A=2047/2048

Answer 7

Ta có :

\(A=\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{10}}\)

=> 2A = \(1+\frac{1}{2}+...+\frac{1}{2^9}\)

Lấy 2A - A = \(\left(1+\frac{1}{2}+...+\frac{1}{2^9}\right)-\left(\frac{1}{2}+...+\frac{1}{2^{10}}\right)\)

= \(1-\frac{1}{2^{10}}=1-\frac{1}{1024}=\frac{1023}{1024}\)

Vậy A = 1023/1024

Answer 8

1023/1024

Answer 9

Cho mk hỏi ^ là gì v?