Start Maple from Start Menu/Program Files or using the icon in f:\math115, or double click on 115lab5base.mws Load the linear algebra progams with the command: > with(linalg): First, let us quickly solve the questions of the midterm using these matrices. The questions are in f:\math115\11504mid.pdf T:=matrix(3,3,[-13,10,15,-30,27,45,10,-10,-18]); R:=matrix(4,4,[2,x,1,0,-1,1,0,1,2,2,x-1,0,4*x-1,1,0,-1]); Q:=matrix(9,9,1):Q:=mulrow(Q,9,-8); S:=matrix(2,2,[-61/2,42,-45/2,31]); Here is something from the book which is too tedious to do without a computer: First, generate a random 4x4 matrix M (make sure it has rank 4) and 4x1 vector b and solve the equation M x = b. Then form four new matrices, each time replacing different columns of M with b. You can use the commands delcols, augment and col here. Calculate the determinants of these 4 matrices and divide each by the determinant of M. Do you notice any connection with the vector x found before? This is Cramer's Rule. Let us now look at vectors, we can define them in a shorthand way: > v1:=vector([1,2,3,-1]); > v2:=vector([-1,2,2,-1]); We can use the matadd commands to add vectors, or just use > evalm(v1-v2); Note that if we don't use evalm it displays them symbolically. Verify that 1/2 times 5v1-4v2 is equal to 5/2 v1 - 2 v2 as expected. We can take the dot product of vectors: > dotprod(v1,v2); Project v2 onto v1 to find an e2 which is orthogonal to v1 > e2:=v2-dotprod(v2,v1)/dotprod(v1,v1)*v1; Note that we use dotprod(v1,v1) for the length of v1 squared. If we define > v3:=vector([-1,0,-3,2]); show that it is obtuse with both of the other vectors. Using the Gram-Schmidt method, find e3 from v3, v2 and v1. Find a fourth orthogonal vector, starting with v4:=vector([0,0,1,0]); then again with > v4:=vector([-2,-1,2,3]); Do the same with v4:=vector([1,0,0,0]); and then try a random v4. Try once more with v4:=vector([7, 12, 31, -16]); What goes wrong here?