Worksheets0B2 Wk6 Tutorial MCQs (Determinants)
Total questions: 9
Worksheet time: 9mins
What is the determinant of A?
-44
-36
28
44
Which of the formulae in the picture is the formula for calculating the determinant of a 3x3 matrix?
a
b
c
d
The (i,j)−th minor Aij of an n×n matrix A is... (select the correct statement)
a) Another name for the (i,j)-th entry of A.
b) The matrix obtained by deleting the i-th row and j-th column of A.
c) The matrix obtained by deleting the j-th row and i-th column of A.
d) The determinant of the matrix obtained by deleting the i-th row and j-th column of A.
Suppose a square matrix B is obtained by swapping rows s and t (s=t) of another square matrix A. Which of the following are true?
a) det(B)=−det(A)
b) det(B)=sdet(A)
c) det(B)=det(A)
d) tdet(B)=det(A)
Suppose a square matrix B is obtained by multiplying row s of another square matrix A by some non-zero scalar μ . Which of the following are true?
a) det(B)=−det(A)
b) det(B)=μdet(A)
c) det(B)=det(A)
d) μdet(B)=det(A)
Suppose U is an n×n matrix in row echelon form. Which of the following can be used to calculate det U ?
a) det U=u11u12...u1n
b) det U=un1un2...unn
c) det U=u1nu2n...unn
d) det U=u11u22...unn
Suppose A is an n×n matrix such that det A=0 . Which of the following are also true?
a) A can be reduced to a matrix in REF which does not have a zero row.
b) A can be reduced to the zero matrix i.e. the n×n matrix whose every entry is 0.
c) A is invertible
d) Any system of linear equations whose LHS is represented by A has a unique solution.
Suppose A is an invertible n×n . Which of the following are also true?
a) A can be reduced to a matrix in REF which does not have a zero row.
b) A can be reduced to the zero matrix i.e. the n×n matrix whose every entry is 0.
c) detA=0 .
d) Any system of linear equations whose LHS is represented by A has a unique solution.
What is the determinant of A?
0
12
18
-12
-18
