Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
1-product_(k=0)^infinity(1-0.8 (1/2)^(k))
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
