Captured On
[2020-02-05 Wed 19:40]
Source
Session 1: Vectors | Part A: Vectors, Determinants and Planes | 1. Vectors and Matrices | Multivariable Calculus | Mathematics | MIT OpenCourseWare

1 Chalkboard

Figure 1: Definition of vectors

Figure 1: Definition of vectors

Figure 2: Length of a vector

Figure 2: Length of a vector

Figure 3: Modules and addition

Figure 3: Modules and addition

Figure 4: Multiplying by scalars

Figure 4: Multiplying by scalars

2 Which is the vector between 2 points?

2.1 Front

Which is the vector between 2 points?

For two points \(P\) and \(Q\)

2.2 Back

  • \(\vb{PQ} = \vb{Q} - \vb{P}\)
  • \(\vb{PQ}\) is the displacement from \(P\) to \(Q\)

3 Which is the notation for vectors and points?

3.1 Front

Which is the notation for vectors and points?

How we can write them?

3.2 Back

  • Points: \((a_1, a_2)\)
  • Vectors:
    • \(<a_1, a_2> = a_1 \vb{i} + a_2 \vb{j}\)
    • \({\displaystyle \vb{P} = \vb{OP}}\) is the vector from the origin to \(P\)
  • A real number is a scalar

4 Which is the magnitude of a vector in 3D?

4.1 Front

Which is the magnitude of a vector in 3D?

\(\abs{\ev{a_1, a_2, a_3}}\)

4.2 Back

5 Which is a unit vector?

5.1 Front

Which is a unit vector?

5.2 Back

Is any vector with unit length \(\hat{u}\)

  • \(\abs{\hat{u}} = 1\)
  • Special vectors
    • \(\hat{i} = \ev{1, 0, 0}\)
    • \(\hat{j} = \ev{0, 1, 0}\)
    • \(\hat{k} = \ev{0, 0, 1}\)

6 How can we get a vector of the median of the triangle?

6.1 Front

How can we get a vector of the median of the triangle?

Triangle: \(ABC\), from vertex: \(A\)

6.2 Back

\({\displaystyle \vb{AM} = \frac{1}{2} (\vec{B} + \vec{C}) - \vb{A}}\)

7 How we can find the unit vector from any vector?

7.1 Front

How we can find the unit vector from any vector?

7.2 Back

\({\displaystyle \hat{u} = \frac{\vb{u}}{|\vb{u}|}}\)