Define group. Show that the set of integers is not a group with respect to subtraction operation.[5]
Linear Equations in Linear Algebra
1.
Reduce the system of equations into echelon form and solve:
x1−2x2−x3+3x4=0
−2x1+4x2+5x3−5x4=3
3x1−6x2−6x3+8x4=2
[10]
2.
When a linear system of equation is consistent? Find the values of h and k for which the system is consistent:
2x1−x2=h
−6x1+3x2=k
[5]
Matrix Algebra
1.
The economy whose consumption matrix C is and the final demand is 50 units for manufacturing, 30 units for agriculture and 20 units for service. Find the production level x that will satisfy this demand.
C=0.50.20.10.40.30.10.20.10.3
[10]
Orthogonality and Least Squares
1.
Find the equation y = a0 + a1 x of the least square line that best fits the data points (0, 1), (1, 1), (1, 1), (2, 2), (3, 2).[10]
Rings and Fields
1.
Define ring. Show that the set of positive integers with respect to addition and multiplication operation is not a ring.[5]
Transformation
1.
Define linear transformation with an example. Let
A=13−1−357,v=[2−1],b=324,x=[x1x2]
and define a transformation T:R2→R2 by T(x)=Ax then
a.find T(v)
b.find x∈R2 whose image under T is b
[10]
2.
The column of I2=[1001] are e1=[10] and e2=[01]. Suppose T is a linear transformation from R2 into R3 such that
T(e1)=51−2,T(e2)=0−18
find a formula for the image of an arbitrary x in R2. That is, find T(x) for x in R2.[2.5+2.5]
Vector Space Continued
1.
Define null space of a matrix A. show that v is null of A.
A=[−15−3−921],v=5−3−2
[5]
Vector Spaces
1.
Determine the column of the matrix A are linearly independent, where
A=−20080−5−103
[5]
2.
When two column vector in R2 are equal? Give an example. Compute u+3v, u−2v, where
u=1−32,v=1−13
[5]
3.
Verify that 1k,−2k,3k are linearly independent signals.[5]
4.
Define unit vector. Find a unit vector of u = (0, -2, 2, -3) in the direction of u.[5]