Question

a = 1/2 + 1/4 + 1/8 + ... +1 / 2024

Answer 1

Sửa đề: \(a=\frac12+\frac14+\frac18+\cdots+\frac{1}{1024}\)

=>\(2a=1+\frac12+\frac14+\cdots+\frac{1}{512}\)

=>\(2a-a=1+\frac12+\frac14+\cdots+\frac{1}{512}-\frac12-\frac14-\cdots-\frac{1}{1024}\)

=>\(a=1-\frac{1}{1024}=\frac{1023}{1024}\)