Added unittest for sineFunction

src/test/c/test_taschenrechner.c

@@ -114,5 +114,10 @@ void test_squareRootFunction(void) {
     TEST_ASSERT_EQUAL_FLOAT(2.0, squareRootFunction(4.0));
 }
 
+// Sine function
+void test_sineFunction(void) {
+    // Your test code here
+    TEST_ASSERT_EQUAL_FLOAT(0.0, sineFunction(0.0));
+}
 
 #endif // TEST