From a24186e7f648a8854a544f14b7b6ffb590f3add2 Mon Sep 17 00:00:00 2001 From: Maciej Topyla <m.m.topyla@student.tudelft.nl> Date: Sun, 4 Sep 2022 11:01:51 +0000 Subject: [PATCH] Fixing figure, adding admonitions --- src/3_vector_spaces.md | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/src/3_vector_spaces.md b/src/3_vector_spaces.md index 7448379..5f5cb26 100644 --- a/src/3_vector_spaces.md +++ b/src/3_vector_spaces.md @@ -41,7 +41,7 @@ We will denote by ${\mathcal V}^n$ the **vector space** composed by all possible The components of a vector, $\{ v_i\}$ can be **real numbers** or **complex numbers**, depending on whether we have a real or a complex vector space. -!!! note +!!! info "Vector basis" Note that the above expression of $\vec{v}$ in terms of its components assume that we are using a 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. @@ -51,22 +51,26 @@ and we can write a generic vector $\vec{v}$ as $$\vec{v} = (v_1, v_2, \ldots, v_n) = v_1 \vec{a}_1 + v_2 \vec{a}_2 + \ldots v_n \vec{a}_n \, .$$ -However, one could choose another different basis, denoted by $\vec{b}_1,\vec{b}_2,\ldots,\vec{b_n}$, where the same vector would be expressed in terms of a different set of components +However, one could choose a different basis, denoted by $\vec{b}_1,\vec{b}_2,\ldots,\vec{b_n}$, where the same vector would be expressed in terms of a different set of components $$ \vec{v} = (v'_1, v'_2, \ldots, v'_n) = v'_1 \vec{b}_1 + v'_2 \vec{b}_2 + \ldots v'_n \vec{b}_n \, .$$ -so while the vector remains the same, the values of its components depends on the specific choice of basis. +Thus, while the vector remains the same, the values of its components depend on the specific choice of basis. -The most common basis is the **Cartesian basis**, where for example for $n=3$ one has +The most common basis is the **Cartesian basis**, where for example for $n=3$: $$\vec{a}_1 = (1, 0, 0) \, ,\qquad \vec{a}_2 = (0, 1, 0)\, ,\qquad \vec{a}_3 = (0, 0, 1) \, .$$ -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. +!!! warning "" + The elements of a vector basis must be **linearly independent** from one another, meaning + that none of them can be expressed as a linear combination of the other basis vectors. We can consider one example in the two-dimensional real vector space $\mathbb{R}$, namely the $(x,y)$ coordinate plane, shown below. - +<figure markdown> +  + <figcaption></figcaption> +</figure> We see how the same vector $\vec{v}$ can be expressed in two different bases. 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. -- GitLab