Normed Vector Spaces
This quiz covers the fundamental concepts and properties of normed vector spaces, a cornerstone of functional analysis and linear algebra.
Questions
In a normed vector space, the distance between two vectors x and y is defined as:
- ||x - y||
- ||x + y||
- ||x|| + ||y||
- ||x|| - ||y||
Which of the following is a property of a norm in a normed vector space?
- Positive Definiteness
- Homogeneity
- Triangle Inequality
- All of the above
A sequence {xn} in a normed vector space is called a Cauchy sequence if:
- ||xn - xm|| → 0 as n, m → ∞
- ||xn|| → 0 as n → ∞
- ||xn - xn+1|| → 0 as n → ∞
- ||xn + xn+1|| → 0 as n → ∞
A normed vector space that is also complete (i.e., every Cauchy sequence converges) is called a:
- Banach Space
- Hilbert Space
- Inner Product Space
- Metric Space
The norm of a linear operator T : X → Y between two normed vector spaces X and Y is defined as:
- ||T|| = sup{||Tx|| : x ∈ X, ||x|| ≤ 1}
- ||T|| = sup{||Tx|| : x ∈ X}
- ||T|| = inf{||Tx|| : x ∈ X, ||x|| = 1}
- ||T|| = inf{||Tx|| : x ∈ X}
In a normed vector space, the closed ball centered at x0 with radius r is defined as:
- {x ∈ X : ||x - x0|| ≤ r}
- {x ∈ X : ||x - x0|| < r}
- {x ∈ X : ||x - x0|| = r}
- {x ∈ X : ||x - x0|| > r}
Which of the following is a property of a closed ball in a normed vector space?
- It is a closed set.
- It is a bounded set.
- It is a convex set.
- All of the above
The dual space of a normed vector space X is denoted as:
- X*
- X+
- X-
- X0
In a normed vector space, the Hahn-Banach theorem states that:
- Every linear functional on a subspace can be extended to a linear functional on the whole space.
- Every bounded linear functional on a subspace can be extended to a bounded linear functional on the whole space.
- Every closed subspace of a normed vector space is complete.
- Every Cauchy sequence in a normed vector space converges.
Which of the following is an example of a Banach space?
- The space of continuous functions on a closed interval [a, b]
- The space of square-integrable functions on the real line
- The space of polynomials with real coefficients
- The space of sequences of real numbers
In a normed vector space, the open ball centered at x0 with radius r is defined as:
- {x ∈ X : ||x - x0|| < r}
- {x ∈ X : ||x - x0|| ≤ r}
- {x ∈ X : ||x - x0|| = r}
- {x ∈ X : ||x - x0|| > r}
Which of the following is a property of an open ball in a normed vector space?
- It is an open set.
- It is a bounded set.
- It is a convex set.
- All of the above
In a normed vector space, the unit ball is defined as:
- {x ∈ X : ||x|| ≤ 1}
- {x ∈ X : ||x|| < 1}
- {x ∈ X : ||x|| = 1}
- {x ∈ X : ||x|| > 1}
Which of the following is a property of the unit ball in a normed vector space?
- It is a closed set.
- It is a bounded set.
- It is a convex set.
- All of the above
In a normed vector space, the norm of a vector x is denoted as:
- ||x||
- ||x||
- |x|
- |x|