fixed typos

glossary/acos/README.md

@@ -10,7 +10,7 @@ vec4 acos(vec4 x)
 ```
 
 ### Parameters
-```x``` specify the value whose arccosine to return.
+```x``` specifies the value whose arccosine to return.
 
 ### Description
 ```acos()``` returns the angle whose trigonometric cosine is ```x```.

glossary/asin/README.md

@@ -10,7 +10,7 @@ vec4 asin(vec4 x)
 ```
 
 ### Parameters
-```x``` specify the value whose arcsine to return.
+```x``` specifies the value whose arcsine to return.
 
 ### Description
 ```asin()``` returns the angle whose trigonometric sine is ```x```.

glossary/atan/README.md

@@ -15,14 +15,14 @@ vec4 atan(vec4 y_over_x)
 ```
 
 ### Parameters
-```y``` specify the numerator of the fraction whose arctangent to return.
+```y``` specifies the numerator of the fraction whose arctangent to return.
 
-```x``` specify the denominator of the fraction whose arctangent to return.
+```x``` specifies the denominator of the fraction whose arctangent to return.
 
-```y_over_x``` specify the fraction whose arctangent to return.
+```y_over_x``` specifies the fraction whose arctangent to return.
 
 ### Description
-```atan()``` returns the angle whose trigonometric arctangent is ```y,x``` or ```y_over_x```, depending on which overload is invoked. In the first overload, the signs of ```y``` and ```x``` are used to determine the quadrant that the angle lies in. The values returned by atan in this case are in the range -PI and PI. Results are undefined if ```x``` is zero.
+```atan()``` returns the angle whose trigonometric arctangent is ```y,x``` or ```y_over_x```, depending on which overload is invoked. In the first overload, the signs of ```y``` and ```x``` are used to determine the quadrant that the angle lies in. The values returned by ```atan``` in this case are in the range -PI and PI. Results are undefined if ```x``` is zero.
 
 For the second overload, ```atan()``` returns the angle whose tangent is ```y_over_x```. Values returned in this case are in the range -PI to PI.