From 4414d80990ba495bbb37a5624a72faa64c46a03b Mon Sep 17 00:00:00 2001 From: Sonia Conesa Boj <s.conesaboj@tudelft.nl> Date: Sat, 29 Aug 2020 13:49:35 +0000 Subject: [PATCH] Update 3_vector_spaces.md --- src/3_vector_spaces.md | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/src/3_vector_spaces.md b/src/3_vector_spaces.md index b85d03f..803ccda 100644 --- a/src/3_vector_spaces.md +++ b/src/3_vector_spaces.md @@ -18,9 +18,7 @@ The lecture on vector spaces consists of two parts, each with their own video: A vector $\vec{v}$ is essentially a mathematical object characterised by both a **magnitude** and a **direction**, that is, an orientation in a given space. -We can express a vector in terms of its individual **components**. - -Let's assume we have an $n$-dimensional space, meaning that the vector $\vec{v}$ can be oriented +We can express a vector in terms of its individual **components**. Let's assume we have an $n$-dimensional space, meaning that the vector $\vec{v}$ can be oriented in different ways along each of $n$ dimensions. The expression of $\vec{v}$ in terms of its components is @@ -34,11 +32,7 @@ The components of a vector, $\{ v_i\}$ can be **real numbers** or **complex numb depending on whether we have a real or a complex vector space. The expression above of $\vec{v}$ in terms of its components assume that we are -using some specific **basis**. - -It is important to recall that the same vector can be expressed in terms of different bases. - -A **vector basis** is a set of $n$ vectors that can be used to generate all the elements +using some specific **basis**. It is important to recall that the same vector can be expressed in terms of different bases. A **vector basis** is a set of $n$ vectors that can be used to generate all the elements of a vector space. For example, a possible basis of ${\mathcal V}^n$ could be denoted by $\vec{a}_1,\vec{a}_2,\ldots,\vec{a_n}$, @@ -54,7 +48,7 @@ so while the vector remains the same, the values of its components depends on th The most common basis is the **Cartesian basis**, where for example for $n=3$ one has -$$\vec{a}_1 = (1, 0, 0) \, ,\qquad \vec{a}_2 = (0, 1, 0)\, ,\qquad \vec{a}_3 = (0, 0, 1) \, ,$$ +$$\vec{a}_1 = (1, 0, 0) \, ,\qquad \vec{a}_2 = (0, 1, 0)\, ,\qquad \vec{a}_3 = (0, 0, 1) \, .$$ The elements of a vector basis must be **linearly independent** from each other, meaning that none of them can be expressed as linear combination of the rest of basis vectors. @@ -63,12 +57,7 @@ Let's consider one example in the two-dimensional real vector space $\mathbb{R}$  -We see how the same vector $\vec{v}$ can be expressed in two different basis. - -In the first one, the Cartesian basis, its components are $\vec{v}=(2,2)$. - - -But in the second basis, the components are different, being instead $\vec{v}=(2.4 ,0.8)$, +We see how the same vector $\vec{v}$ can be expressed in two different basis. In the first one (left panel), the Cartesian basis, its components are $\vec{v}=(2,2)$. But in the second basis (right panel), the components are different, being instead $\vec{v}=(2.4 ,0.8)$, though the magnitude and direction of the vector itself remain unchanged. ## Properties of a vector space -- GitLab