Failed to render \boxed{\sqrt{6}}

[huangdade]

Failed to render \boxed{\sqrt{6}}

[adamwadesmith]

+1. Solving this requires pulling in the ams package.

[xj168]

+1. Solving this requires pulling in the ams package.

How did I do it, please get an example, thank you

[peanut2001]

很奇怪，我竟然识别不了