Math Problem Statement

Write the cross product of (1,2,0) and (1,4,2)

Solution

The cross product of two vectors A = (1, 2, 0) and B = (1, 4, 2) is given by the determinant of the following matrix:

\begin{vmatrix} \mathbf{i} & \mathbf{j} & \mathbf{k} \\ 1 & 2 & 0 \\ 1 & 4 & 2 \\ \end{vmatrix}$$ This can be expanded as: $$\mathbf{A} \times \mathbf{B} = \mathbf{i} \begin{vmatrix} 2 & 0 \\ 4 & 2 \end{vmatrix} - \mathbf{j} \begin{vmatrix} 1 & 0 \\ 1 & 2 \end{vmatrix} + \mathbf{k} \begin{vmatrix} 1 & 2 \\ 1 & 4 \end{vmatrix}$$ Now, let's compute each of these determinants: 1. For $$\mathbf{i}$$: $$\begin{vmatrix} 2 & 0 \\ 4 & 2 \end{vmatrix} = (2 \cdot 2) - (0 \cdot 4) = 4$$ 2. For $$\mathbf{j}$$: $$\begin{vmatrix} 1 & 0 \\ 1 & 2 \end{vmatrix} = (1 \cdot 2) - (0 \cdot 1) = 2$$ 3. For $$\mathbf{k}$$: $$\begin{vmatrix} 1 & 2 \\ 1 & 4 \end{vmatrix} = (1 \cdot 4) - (2 \cdot 1) = 2$$ So, putting it all together: $$\mathbf{A} \times \mathbf{B} = 4\mathbf{i} - 2\mathbf{j} + 2\mathbf{k}$$ Therefore, the cross product is: $$\mathbf{A} \times \mathbf{B} = (4, -2, 2)$$ Would you like further details or clarifications? Here are 5 related questions for you to explore: 1. What is the physical significance of the cross product in physics? 2. How do you find the magnitude of the cross product? 3. Can the cross product be used in higher dimensions? 4. How does the cross product differ from the dot product? 5. What is the geometric interpretation of the cross product? **Tip**: The cross product is perpendicular to the plane formed by the two vectors, following the right-hand rule.

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Math Problem Analysis

Mathematical Concepts

Vector Algebra
Cross Product
Determinants

Formulas

Cross product of two vectors A × B = det |i j k| |A1 A2 A3| |B1 B2 B3|
Determinant of a 2x2 matrix: |a b| |c d| = (ad - bc)

Theorems

Cross Product Theorem

Suitable Grade Level

Grades 10-12