Let and . If is an eigenvector of , what is its eigenvalue?
7 Eigenvalues and Eigenvectors Online Quiz Questions
Use this free practice quiz with 20 questions to review 7 Eigenvalues and Eigenvectors, test your knowledge, and prepare for your next test or exam.
What are the eigenvalues of A=[2104]?
- A
2 and 4
- B
1 and 8
- C
-2 and -4
- D
2 and -4
Suppose the columns of P are v1 and v2, where Av1=7v1 and Av2=−v2. Which diagonal matrix D satisfies A=PDP−1?
- A
D=[−1007]
- B
D=[70−10]
- C
D=[700−1]
- D
D=[1001]
A 2×2 matrix has characteristic polynomial p(λ)=(λ−6)2, and its eigenspace for λ=6 has dimension 1. Which conclusion is justified?
- A
It is diagonalizable because it has an eigenvalue.
- B
It is not diagonalizable because the eigenspace dimension is less than the algebraic multiplicity.
- C
It is diagonalizable because its characteristic polynomial has a repeated root.
- D
It cannot have any eigenvectors because its eigenvalue is repeated.
Select all statements that are true for the eigenspace associated with an eigenvalue λ.
- A
The eigenspace Eλ contains the zero vector.
- B
The zero vector is an eigenvector.
- C
Eλ=ker(A−λI).
- D
The nonzero vectors in Eλ are precisely the eigenvectors associated with λ.
For an n×n matrix over a field F, select all conditions that are equivalent to diagonalizability over F.
- A
The vector space has a basis consisting of eigenvectors of A.
- B
The total dimension of the eigenspaces is n.
- C
Every eigenvalue must be distinct.
- D
For every eigenvalue, geometric and algebraic multiplicities agree, and the characteristic polynomial splits over the field.
Suppose the eigenspace for λ=6 is E6=span⎩⎨⎧101,010⎭⎬⎫. What is the geometric multiplicity of 6?
What is the standard term for the number of times an eigenvalue occurs as a root of the characteristic polynomial?
Complete the definition: The eigenspace associated with λ is Eλ=.
Complete both identities used in diagonalization: if the columns of P are appropriately ordered eigenvectors, then AP=, and if P is invertible, A=.
Diagonalize A=[1013]. Find both eigenvalues, an eigenvector for each eigenvalue, and matrices P and D such that A=PDP−1. Explain why P is invertible.
Which statement correctly describes how the underlying field can affect diagonalizability?
- A
A matrix has the same diagonalizability status over every field.
- B
A real matrix may fail to be diagonalizable over R because of complex eigenvalues, yet be diagonalizable over C.
- C
A real matrix with complex eigenvalues has no eigenvectors over C.
- D
Changing the field changes only the notation, not the available eigenvalues.
True or false: Eigenvectors corresponding to distinct eigenvalues of a matrix are necessarily linearly independent.
- A
True
- B
False
What is the standard term for the dimension of the eigenspace associated with an eigenvalue?
True or false: For an n×n matrix, defining the characteristic polynomial as det(λI−A) or as det(A−λI) produces the same eigenvalues.
- A
True
- B
False
For B=[2012], what is the algebraic multiplicity of the eigenvalue λ=2?
Which condition is equivalent to diagonalizability of an n×n matrix over its underlying field?
- A
It has at least one eigenvalue.
- B
Every eigenvalue is positive.
- C
The sum of the dimensions of its eigenspaces is n.
- D
Its characteristic polynomial has degree less than n.
A real matrix has a pair of nonreal complex eigenvalues. Which statement is correct?
- A
It is diagonalizable over R because every real matrix has real eigenvalues.
- B
It may fail to be diagonalizable over R but be diagonalizable over C.
- C
It cannot be diagonalizable over either field.
- D
Changing the field changes the matrix entries but not its eigenvalues.
If D=[200−1], what is D3?
- A
[600−3]
- B
[200−1]
- C
[800−1]
- D
[9001]
True or false: If a nonzero vector v satisfies Av=−3v, then the transformation represented by A reverses the direction of v and triples its length.
- A
True
- B
False