EE472 - Control Theory II - Summer 2018 Homework 1: (Only Problems With Will Be Graded)
EE472 - Control Theory II - Summer 2018 Homework 1: (Only Problems With Will Be Graded)
EE472 - Control Theory II - Summer 2018 Homework 1: (Only Problems With Will Be Graded)
Homework 1
(Only problems with * will be graded)
Question 1*: Check whether the following sets of vectors are linearly independent or
not. If they are linearly dependent, then find a non-trivial linear combination of them
which is zero.
1 0 1
3 1 5
1 1 17 0 1 3
a) , , , b) 6 , 0 , 12 , c) , , .
1 3 20 1 1 4
4 1 9
2 3 10
Question 2:
a) Find a basis for the subspace S of R3 defined by the equation 2x -4y + 5z = 0
b) Verify that v1 = [4 2 0]T S and find a basis for S which includes v1.
1 -1 -3 2 -6
-1 2 -7 4 1
2 3 -1 1 6
A1 , A2 3 1 0 0 2
3 7 1 0 18
6 1 3 -2 3
4 6 -2 1 13
a) Reduce these matrices to their row echelon form.
b) Reduce these matrices to their reduced row echelon form. Check your answer
using MATLAB.
c) Compute the rank of these matrices.
Question 4: Find i) a basis of the column-space ii) a basis of the row-space and iii) a
basis of the null-space of the matrices given below and then deduce their ranks.
1 1 2 0 1 3
3 2 4 -3 9
-1 1 -5 9 1 2 1 4 0 3 2
a) A , b) A -2 1 -5 -5 -20 c) A
2 -2 10 -13 -2 , 3
1 2
4 -1 9 7 34 0 0 0 1 3 0
7 4 2 -50 4
5 7 3 -16 -7 3 0 2 4 3 2
Question 5*:
a) Find the rank of the following matrix for the different values of a, b and c.
1 0 0
c a 4 5 b
A
0 b 5 a 4
0 0 3c
b) If b [b1 b2 b3 b4 ]T , characterize all vectors b such that Ax=b is solvable.
c) If a=5 and b=2 and c=0, solve the equation Ax= [4 6 15 0]T
Question 6:
a) A vector space V consists of the vectors {v1 , v2 , v3 , v4 } and all their linear
combinations. Determine the dimension and a basis for V if
v1 [3 -2 4 5 6]T , v2 [1 6 7 3 2]T v3 [ 17 42 68 39 34]T and
v4 [6 5 3 2 1]T .
b) Is the basis you found unique? Justify your answer.
c) Is it possible to express v [133 393 650 367 321]T as a linear combination of
{v1 , v2 , v3 , v4 } ? Justify your answer.
1 0 1 3 2 1
3 4
A1 2 1 4 , A2 1 2 1 , A3 .
2 3
1 1 9 0 5 6
1 1 1 0 1 1 14
a) , , b) , , c) , , ,
2 1 2 0 2 2 19
1 2 1 1 1 1 1
d) 2 , 4 , e) 2 , 0 , f) 2 , 0 , 4 ,
3 6 3 1 3 1 9
Question 13: For which real numbers are the following vectors linearly independent
T T T
in R3? u1 1 1 , u2 1 0 , u3 1 1 .
a b c
Question 14: Find the conditions on a, b, c such that A
1 1 1
a) rank A =1 b) rank A = 2.
a) Find a basis of the column space of A, a basis of the row space of A and a basis
of the nullspace of A.
b) Find the rank of A.
c) Find the dimensions of the column space of A and the nullspace of A.
d) If b [b1 b 2 b3 b 4 ]T , characterize all vectors b such that Ax=b is solvable.
e) If b [1 1 1 1]T , is the equation Ax=b solvable? If yes, find all solutions.
f) If b [1 1 1 2]T , is the equation Ax=b solvable? If yes, find all solutions.
Question 16:
a) Find the rank of the following matrices:
0 1 0 4 1 1 1 2 3 4
A1 0 0 0 A2 3 2 0 A3 0 1 2 2
0 0 1 1 1 0 0 0 0 1
b) Find the range spaces and null spaces of the above matrices.
Question 17:
a) Find the general solution of the equation:
1 2 3 4 3
0 1 2 2 x 2
0 0 0 1 1
b) Find the solution that has the smallest Euclidean norm.
Question 18*:
a) A vector space V consists of the vectors {v1 , v2 , v3 , v4 } and all their linear
combinations. Determine the dimension and the basis for V if
v1 [1 2 3 4 5]T , v2 [1 3 5 6 7]T v3 [1 3 6 8 9]T and
v4 [1 3 6 10 12]T .
Is the basis unique? Justify your answer.
b) Is it possible to express v [5 4 3 2 1]T as a linear combination of
{v1 , v2 , v3 , v4 } ? Justify your answer.
Question 19:
a) Determine whether the vectors v1 [3 1 4]T , v2 [2 3 5]T , v3 [5 2 9]T
and v4 [1 4 1]T span IR 3 ?
b) Determine whether the following polynomials span P2 (the set of all polynomials of
order less than or equal 2)
p1 1 x 2 x 2 , p2 3 x , p3 5 x 4 x 2 and p4 2 2 x 2 x2
Question 20:
a) Determine the dimensions of the following subspaces of R4.
T
i. All vectors of the form a b c 0 .
T
ii. All vectors of the form a b c d with d = a + b, c = a – b.
T
iii. All vectors of the form a b c d with a = b = c = d.
T
iv. All vectors of the form a b c d with a = 2b + c, b = d – a,
c = 2a – b – d.
b) Find a basis for the space in (a), i, and find the coordinate vector of
T
1 1 0 2 with respect to this basis.