The square root function should have only one argument. Mathematica prints a message to warn you that you have given two arguments here.
You can suppress the message for one evaluation using Quiet.
The message reappears without the use of Quiet.
Each message has a name. You can switch off messages for all evaluations using Off.
The message Sqrt::argx has now been switched off, and will no longer appear.
This switches Sqrt::argx back on again.
|Quiet[expr]||evaluate expr without printing any messages|
|Off[Function::tag]||switch off (suppress) a message|
|On[Function::tag]||switch on a message|
|© 2013 Wolfram Research, Inc.|