Let an operation ∗ be defined on Q+ by a∗b=2ab. Then show that Q+ forms a group.[5]
Linear Equations in Linear Algebra
1.
Define system of linear equations. When a system of equation is consistent? Determine if the system is consistent:
−2x1−3x2+4x3=5
x2−2x3=4
x1+3x2−x3=2
[10]
Matrix Algebra
1.
Find the LU factorization of
2−42−64−5−50−13−475−81−3−2181
[10]
2.
If A=[7−421], find a formula for An, where A=PDP−1, P=[1−11−2] and D=[5003][5]
Orthogonality and Least Squares
1.
Find a least square solution of the inconsistent system Ax=b for
A=−12−12−33,b=421
[10]
Rings and Fields
1.
Define ring and show that set of real numbers with respect to addition and multiplication operation is 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+0]
2.
Let A=[0−110] and define T:R2→R2 by T(x)=Ax, find the image under T of
u=[1−3],v=[15]
[5]
Vector Space Continued
1.
Define null space of a matrix A. Let
A=[−15−3−921],v=5−3−2
Then show that v is in the null A.[5+0]
Vector Spaces
1.
Determine the column of the matrix A are linearly independent, where
A=0151284−10
[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.
Find a unit vector v of u=(1,−2,2,3) in the direction of u.[5]
4.
Prove that the two vectors u and v are perpendicular to each other if and only if the line through u is perpendicular bisector of the line segment from −u to v.[5]
5.
Verify that 1k,(−2k),3k are linearly independent signals.[5]