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.
将 y = sqrt(4 - x^2) 在 [-2, 2] 上绕x轴旋转。(确定得到的立体。)
将 y = sqrt(4 - x^2) 在 [-2, 2] 上绕x轴旋转。(确定得到的立体。)
Natural Language
Math Input
Extended Keyboard