Exercise 3 1
1. **Problem Statement:** Given points P = (3, -1), Q = (-4, -6), R = (1, 4), and S = (2, 5), find the following vectors in component form:
(i) Vector $\overrightarrow{PQ}$
(ii) $3\overrightarrow{PQ} - \overrightarrow{RS}$
(iii) $2\overrightarrow{PR} + 3\overrightarrow{PS}$
(iv) Verify if $\frac{1}{2} \overrightarrow{PQ} + \frac{5}{2} \overrightarrow{PR} = \frac{3}{2} \overrightarrow{QS}$
(v) $3^2 \overrightarrow{PS} - 4^2 \overrightarrow{SP} + \overrightarrow{QP}$
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2. **Problem Statement:**
(i) Show that points A(1, 0), B(6, 0), and C(0, 0) are collinear.
(ii) Given position vectors $\mathbf{a} = (2, -7)$ and $\mathbf{b} = (\frac{m}{2}, 11)$, find $m$ such that $\mathbf{a}$ and $\mathbf{b}$ are collinear.
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3. **Problem Statement:** Given vectors $\mathbf{\bar{u}} = \langle -1, 1 \rangle$, $\mathbf{\bar{v}} = \langle 0, 1 \rangle$, and $\mathbf{\bar{w}} = \langle 3, 4 \rangle$:
(i) Find $x$ satisfying $\mathbf{\bar{u}} - 2x = x - \mathbf{\bar{w}} + 3\mathbf{\bar{v}}$
(ii) Find $\mathbf{\bar{u}}$ and $\mathbf{\bar{v}}$ if $\mathbf{\bar{u}} + \mathbf{\bar{v}} = \langle 2, -3 \rangle$ and $3\mathbf{\bar{u}} + 2\mathbf{\bar{v}} = \langle -1, 2 \rangle$
(iii) Find the initial point of $\mathbf{v} = \langle -3, 1, 2 \rangle$ if its terminal point is $(5, 0, 1)$.
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4. **Problem Statement:**
(i) Find $m$ such that $\mathbf{a} = 3\mathbf{i} + 4\mathbf{j} - 9\mathbf{k}$ is parallel to $\mathbf{b} = \mathbf{i} + m\mathbf{j} - 3\mathbf{k}$.
(ii) Find $\lambda$ such that points $P, Q, R$ with position vectors $\mathbf{i} + 2\mathbf{j} + 3\mathbf{k}$, $-2\mathbf{i} + 3\mathbf{j} + 5\mathbf{k}$, and $2\lambda - \mathbf{k}$ respectively are collinear.
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5. **Problem Statement:**
(i) Given $\mathbf{a} = \mathbf{i} - 2\mathbf{j} + \mathbf{k}$, $\mathbf{b} = \mathbf{i} - \mathbf{j} - \mathbf{k}$, and $\mathbf{c} = 2\mathbf{i} + \mathbf{k}$, find a unit vector in the direction of $2\mathbf{a} - 3\mathbf{b} + \mathbf{c}$.
(ii) Use vectors to find the lengths of diagonals of a parallelogram with adjacent sides $\mathbf{i} + \mathbf{j}$ and $\mathbf{i} - 2\mathbf{j}$.
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6. **Problem Statement:**
(i) Show that points with position vectors $\mathbf{i} - \mathbf{j}$, $4\mathbf{i} + 3\mathbf{j} + \mathbf{k}$, and $2\mathbf{i} - 4\mathbf{j} + 5\mathbf{k}$ form a right-angled triangle.
(ii) Show that points with position vectors $2\mathbf{i} + 3\mathbf{j} + \sqrt{3}\mathbf{k}$, $\sqrt{10}\mathbf{i} - \mathbf{j} + \sqrt{5}\mathbf{k}$, and $-3\mathbf{i} + \sqrt{3}\mathbf{j} + 2\mathbf{k}$ form an equilateral triangle.
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7. **Problem Statement:**
(i) Find $\lambda$ such that $|\mathbf{a}| = |3\mathbf{b}|$ where $\mathbf{a} = \mathbf{i} - 3\mathbf{j} + \lambda \mathbf{k}$ and $\mathbf{b} = \mathbf{i} + 2\mathbf{j} - \mathbf{k}$.
(ii) Given $\mathbf{a} = 2\mathbf{i} + 3\mathbf{j}$ and $\mathbf{b} = -3\mathbf{i} + 2\mathbf{j}$, check if $|\mathbf{a}| = |\mathbf{b}|$ or $\mathbf{a} = \mathbf{b}$.
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8. **Problem Statement:** Given $\mathbf{a} = 2\mathbf{i} - 3\mathbf{j} + \mathbf{k}$ and $\mathbf{b} = \mathbf{i} - 3\mathbf{j} + 5\mathbf{k}$:
(i) Find a vector of magnitude 5 in the direction of $\mathbf{a} - 2\mathbf{b}$.
(ii) Find a vector of magnitude 3 opposite in direction to $3\mathbf{a} + \mathbf{b}$.
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9. **Problem Statement:** The position vectors of points A and B are $\mathbf{i} - 2\mathbf{j} + \mathbf{k}$ and $2\mathbf{i} + 3\mathbf{j} - \mathbf{k}$ respectively.
(i) Find the position vector of point P dividing the line segment joining A and B internally in the ratio 2:3.
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**Note:** The above restates all problems from Exercise 3.1 as requested.