Mention sqrt() on the constants pages (mdn#19978)

Author: Josh-Cena

files/en-us/web/javascript/reference/global_objects/math/sqrt1_2/index.md

@@ -18,6 +18,8 @@ The **`Math.SQRT1_2`** property represents the square root of 1/2 which is appro
 
 ## Description
 
+`Math.SQRT1_2` is a constant and a more performant equivalent to [`Math.sqrt(0.5)`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/sqrt).
+
 Because `SQRT1_2` is a static property of `Math`, you always use it as `Math.SQRT1_2`, rather than as a property of a `Math` object you created (`Math` is not a constructor).
 
 ## Examples

files/en-us/web/javascript/reference/global_objects/math/sqrt2/index.md

@@ -18,6 +18,8 @@ The **`Math.SQRT2`** property represents the square root of 2, approximately 1.4
 
 ## Description
 
+`Math.SQRT2` is a constant and a more performant equivalent to [`Math.sqrt(2)`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/sqrt).
+
 Because `SQRT2` is a static property of `Math`, you always use it as `Math.SQRT2`, rather than as a property of a `Math` object you created (`Math` is not a constructor).
 
 ## Examples