Given a list of points that form a polygon when joined sequentially, find if this polygon is convex (Convex polygon definition). Note: There are at least 3 and at most 10,000 points. Coordinates are in the range -10,000 to 10,000. You may assume the polygon formed by given points is always a simple polygon (Simple polygon definition). In other words, we ensure that exactly two edges intersect at each vertex, and that edges otherwise don't intersect each other. Example 1: [[0,0],[0,1],[1,1],[1,0]] Answer: True Explanation: Example 2: [[0,0],[0,10],[10,10],[10,0],[5,5]] Answer: False Explanation: