btVector3 vec(2, 5, 9); float x = vec.getX(); // x = 2
btVector3 vec1(2, 5, 9); btVector3 vec2(4, 7, 1); float x1 = vec1.getX(); float x2 = vec2.getX(); // x1 = 2, x2 = 4In this example, the getX method is used to retrieve the x-coordinate values of two btVector3 objects, `vec1` and `vec2`. Overall, the getX method is used to retrieve the x-coordinate value of a btVector3 object. The btVector3 library is a package that provides various mathematical functions related to 3D vectors and matrices.