   MathJax.typesetPromise([feedbackDiv]);
            });
        });

        function getCorrectFeedback(index) {
                switch (index) {
                    case 0:
                        return "The text states that scaling, translation, addition, Cartesian product, projection, and intersection preserve convexity. It does not mention the union. In fact, the union of two convex sets is not necessarily convex (e.g., take the union of two distinct points).";
                    case 1:
          