diff --git a/src/main/c/Calculator/calculator.c b/src/main/c/Calculator/calculator.c
index 8b75156..4cfafd2 100644
--- a/src/main/c/Calculator/calculator.c
+++ b/src/main/c/Calculator/calculator.c
@@ -101,7 +101,12 @@ double combination(int n, int r);
         case 14:
             return pow(num1, num2);
         case 15:
-            return sin(num1 * M_PI / 180.0);      
+            return sin(num1 * M_PI / 180.0); 
+        case 16:
+            return cos(num1 * M_PI / 180.0);
+        case 17:
+            return tan(num1 * M_PI / 180.0);
+