Question

Rút gọn biểu thức: A= 1+1/2+1/2^2+1/2^3+...+1/2^2012

 

Answer 1

A = 1+1/2+1/2^2+1/2^3+.....+1/2^2012

2A= 2. (1+1/2+1/22+1/23+.....+1/22012)

2A= 2 + 1 + 1/2 + 1/22 + 1/23 + ...+ 1/22011

2A - A= (2 + 1 + 1/2 + 1/22 + 1/23+ ...+ 1/22011) - (1+1/2+1/22+1/23+.....+1/22012)

1A= 2 + 1 + 1/2 + 1/22 + 1/23 + ...+ 1/22011 - 1-1/2-1/22+1/23+.....+1/22012

1A= 2 - 1/22012

A= 2-1/22012

A= 2 - 1/22012

số mũ nữa nha

Answer 2

\(A=1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2012}}\)

\(2A=2+1+\frac{1}{2}+...+\frac{1}{2^{2011}}\)

\(2A-A=\left(2+1+\frac{1}{2}+...+\frac{1}{2^{2011}}\right)-\left(1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2012}}\right)\)

\(A=2-\frac{1}{2^{2012}}\)

Answer 3

A=2- 1/2^2012

Answer 4

2A=2+1+1/2|+...+1/2^2011

2A-A=(2+1+1/2+...1/+2^2011)+(1+1/2+...+1/2^2012)

A=2-1/2^2012

Answer 5

Tính biểu thức

1/2+1/2^2+1/2^3+...+1/2^2020