+9673 I don't understand vectors, something like i, j, k, norm of the vector, length?? directions?? matrices?? I just don't understand.
+33661 Geometrically, in 2 dimensions i and j represent unit length vectors in the x and y directions respectively. In 3 dimensions k represents the unit vector in the z direction. The norm is the square root of the sum of the squared components (the coefficients of i, j and k), and gives the length of the vector.
