Expert Answer
Adjacency matrix is the square matrix which has rows and columns contains the information whether the vertices are adjacent to each other or not.Here there are 4 vertices 1, 2, 3, and 4.Now the matrix consists of :1 in the corresponding cell (i,j) means there is a edge between the vertex "i" to "j".0 in the corresponding cell (i,j) means there is no edge between the vertex "i" to "j"