Merge pull request w3c#4112 from ewilligers/minus-1

[css-values] sin and cos can reach -1

Author: tabatkins

css-values-4/Overview.bs

@@ -2588,8 +2588,8 @@ Trigonometric Functions: ''sin()'', ''cos()'', ''tan()'', ''asin()'', ''acos()''
 	all represent the same value,
 	approximately ''.707''.)
 	They all represent a <<number>>;
-	''sin()'' and ''cos()'' will always return a number between -1 and 1,
-	while ''tan()'' can return any number between +∞ and −∞.
+	''sin()'' and ''cos()'' will always return a number between −1 and 1,
+	while ''tan()'' can return any number between −∞ and +∞.
 	(See [[#calc-type-checking]] for details on how [=math functions=] handle ∞.)
 
 	The <dfn lt="asin()">asin(A)</dfn>, <dfn lt="acos()">acos(A)</dfn>, and <dfn lt="atan()">atan(A)</dfn> functions