Vector Operations 2F4Cb5
1. **State the problem:**
We are given two vectors:
$$a = \begin{pmatrix}1 \\ 2\end{pmatrix}, \quad b = \begin{pmatrix}-3 \\ 5\end{pmatrix}$$
We need to:
(i) Draw and label vector $2a$.
(ii) Draw and label vector $(a - b)$.
2. **Formula and rules:**
- To multiply a vector by a scalar, multiply each component by that scalar:
$$2a = 2 \times \begin{pmatrix}1 \\ 2\end{pmatrix} = \begin{pmatrix}2 \times 1 \\ 2 \times 2\end{pmatrix} = \begin{pmatrix}2 \\ 4\end{pmatrix}$$
- To subtract vectors, subtract corresponding components:
$$a - b = \begin{pmatrix}1 \\ 2\end{pmatrix} - \begin{pmatrix}-3 \\ 5\end{pmatrix} = \begin{pmatrix}1 - (-3) \\ 2 - 5\end{pmatrix} = \begin{pmatrix}4 \\ -3\end{pmatrix}$$
3. **Intermediate work:**
- For $2a$, the vector is $\begin{pmatrix}2 \\ 4\end{pmatrix}$.
- For $a - b$, the vector is $\begin{pmatrix}4 \\ -3\end{pmatrix}$.
4. **Explanation:**
- Vector $2a$ points to the coordinate $(2,4)$ on the grid. This means starting from the origin $(0,0)$, move 2 units right and 4 units up.
- Vector $(a - b)$ points to $(4,-3)$, meaning from the origin move 4 units right and 3 units down.
5. **Final answer:**
(i) Vector $2a = \begin{pmatrix}2 \\ 4\end{pmatrix}$.
(ii) Vector $a - b = \begin{pmatrix}4 \\ -3\end{pmatrix}$.
These vectors can be drawn on their respective grids as instructed.