one math problem. thx

alexmingzhu

A sequence of numbers is 1/2, 1/4, 1/8, 1/16, 1/32, what is the range of the tenth number a₁₀ in the sequence?

(Key: 0.0001<a₁₀<0.001)

please tell me how to work it out, thank you very much.

robert

0.001=1/(2×5)³

0.0001=1/(2×5)⁴

stevegt

a_{10= 1/1024   这个记住就行了}

_{不是每道题目非要正儿八经推出来，有时候技巧也重要。}