Which description defines a basis for a vector space?
5 Vector Spaces Online Quiz Questions
Use this free practice quiz with 20 questions to review 5 Vector Spaces, test your knowledge, and prepare for your next test or exam.
What is the dimension of the real polynomial space P2, consisting of polynomials of degree at most 2?
An expression of the form c1v1+c2v2+⋯+ckvk is called a .
Select all statements that are always true for sets of vectors in Rn.
- A
Any set with more than n vectors in Rn is linearly dependent.
- B
Every linearly independent set in Rn has at most n vectors.
- C
Every set with exactly n vectors in Rn is a basis.
- D
Every spanning set in Rn must have exactly n vectors.
Let v1=(1,2,0) and v2=(0,1,1). Which vector belongs to span{v1,v2}?
- A
(3,8,2)
- B
(3,7,2)
- C
(1,2,1)
- D
(2,5,1)
True or false: If the order of the vectors in an ordered basis changes, the coordinate vector of a fixed vector may also change.
- A
True
- B
False
For W={(x,y,z,w)∈R4:x+y+z+w=0}, solve for w: w=. A basis obtained from the free variables is {(1,0,0,),(0,1,0,−1),(0,0,1,−1)}.
Select all conclusions that necessarily follow when a set of vectors contains the zero vector.
- A
The set is linearly dependent.
- B
The set cannot be a basis.
- C
The set must span the entire vector space.
- D
The set must contain no nonzero vectors.
What is dim(M2×2), the vector space of all real 2×2 matrices?
- A
2
- B
3
- C
4
- D
6
Find a basis for the column space of A=101011112, and explain why your chosen columns form a basis.
If PB is the matrix whose columns are the vectors of an ordered basis B, which equation reconstructs v from its coordinate vector?
- A
[v]B=PBv
- B
v=PB[v]B
- C
v=PB−1[v]B
- D
[v]B=v+PB
Which subset of R3 is not a subspace?
- A
{(x,y,z)∈R3:x+y+z=0}
- B
{(x,y,z)∈R3:x+y+z=1}
- C
R3
- D
{(x,y,z)∈R3:z=0}
True or false: In an n-dimensional vector space, any set of exactly n linearly independent vectors is a basis.
- A
True
- B
False
Which statement about the span of a set of vectors is necessarily true?
- A
The span is always a subspace.
- B
The span is never a subspace.
- C
The span always excludes the zero vector.
- D
The span must equal the entire ambient vector space.
What is the dimension of the polynomial space P5, consisting of real polynomials of degree at most 5?
Which conclusion follows for a set containing more than n vectors in Rn?
- A
Any set of more than n vectors in Rn is linearly dependent.
- B
Any set of more than n vectors in Rn spans Rn.
- C
Any set of fewer than n vectors in Rn is linearly dependent.
- D
Every set of n vectors in Rn is a basis.
Let v1=(1,2,0), v2=(0,1,1), and w=(3,8,2). If w=av1+bv2, what is the scalar coefficient b?
When row reduction identifies pivot columns for a matrix, which columns form a basis for the column space?
- A
Use the nonpivot columns of the row-reduced matrix.
- B
Use the pivot columns of the original matrix.
- C
Use every column of the row-reduced matrix.
- D
Use the nonzero rows of the original matrix.
True or false: Let W be a nonempty subset of a vector space V. If cu+dv∈W for every u,v∈W and all scalars c,d, then W is a subspace of V.
- A
True
- B
False
Let p(x)=1−2x+3x2 and q(x)=4+x−x2. What is the coefficient of x2 in 2p(x)−3q(x)?