**Purpose:**Usage help for the

**sqrt**math function.

The call,

[expr { sqrt($x) }]returns the square root of $x.

If you're using

*sqrt*in connection with the Pythagorean Theorem:

[expr { sqrt( $x * $x + $y * $y ) }]note that Tcl provides a hypot function, which gives a more concise formula:

[expr { hypot( $x, $y ) }]The hypot function is also more robust in that it will get overflow and underflow less often when dealing with very large or very small numbers.

See also: isqrt