refactoring: description added

src/trigonometricFunctions.c

@@ -3,7 +3,7 @@
 #include "math.h"
 #include <stdio.h>
 #include <stdlib.h>
-
+//function for trigonometric
 double* calculate_sin_double(double angle) {
     double* result= malloc(sizeof (double));
     *result=sin(angle);