refactoring: case(for pow and sine)

src/main/c/Calculator/calculator.c

@@ -97,7 +97,11 @@ double combination(int n, int r);
         case 12:
             return cbrt(num1);
         case 13:
-            return factorial(num1);  
+            return factorial(num1);
+        case 14:
+            return pow(num1, num2);
+        case 15:
+            return sin(num1 * M_PI / 180.0);