Special Matrices

10. A column vector (also called a column matrix) is a matrix of the size $n \times 1$.
    • The number $n$ in a $n \times 1$ column vector is the vector size of the column vector.
    • Every $n \times m$ matrix consists of at least one column vector.
    • We use the notation of row vectors to denote column vectors, too: $\vec{v}$ (

      $\vec{v}$

      ) or $\textbf{v}$ (

      $\textbf{v}$

      ), usually with a subscript, like $\vec{v}_1$ (

      $\vec{v}_1$

      ).
    
    Examples:

    2. $E = \vec{v}_4 = \begin{bmatrix} 😀 \\ 😁 \\ 😎 \\ 😜 \end{bmatrix}$

    3. $S = \vec{v}_5 = \begin{bmatrix} \text{Bla} \end{bmatrix}$

    37. $\vec{v}_6 = \begin{bmatrix} x \\ y \end{bmatrix}$

    38. $\vec{v}_7 = \begin{bmatrix} 🔴 \\ 🟡 \\ 🟢 \end{bmatrix}$

    39. $\vec{v}_8 = \begin{bmatrix} 1 \\ 1 \end{bmatrix}$