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.
関数 f: {1, 2, 3} -> {a, b} は何個存在しますか?
関数 f: {1, 2, 3} -> {a, b} は何個存在しますか?
Natural Language
Math Input
Extended Keyboard