Math Problem Statement

isnt that formula the same as the cross product one

Solution

It sounds like you're referring to a formula related to vectors, and you're wondering if it's the same as the cross product formula.

Let's clarify: The cross product (also called the vector product) is a way to multiply two vectors in three-dimensional space. The formula for the cross product of vectors A = (a₁, a₂, a₃) and B = (b₁, b₂, b₃) is:

A×B=(a2b3a3b2,a3b1a1b3,a1b2a2b1)\mathbf{A} \times \mathbf{B} = (a_2b_3 - a_3b_2, a_3b_1 - a_1b_3, a_1b_2 - a_2b_1)

This gives a new vector that is perpendicular to both A and B, and its magnitude is given by:

A×B=ABsin(θ)|\mathbf{A} \times \mathbf{B}| = |\mathbf{A}| |\mathbf{B}| \sin(\theta)

where θ\theta is the angle between the two vectors.

Is it the same as another formula?

The answer depends on which formula you're comparing it to. If you're thinking of the determinant of a 3x3 matrix involving vectors (which is used for the cross product), then yes, they are essentially the same thing, since the cross product can be computed using the determinant of a matrix with the unit vectors i, j, k as the first row and the components of vectors A and B as the second and third rows:

\mathbf{i} & \mathbf{j} & \mathbf{k} \\ a_1 & a_2 & a_3 \\ b_1 & b_2 & b_3 \end{vmatrix}$$ But if you're referring to a different formula (like one for dot products, magnitudes, or angles), then that might be different. Let me know if you'd like more detail on a specific formula!

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Math Problem Analysis

Mathematical Concepts

Vector Algebra
Cross Product
Determinants

Formulas

Cross product formula: A × B = (a2b3 - a3b2, a3b1 - a1b3, a1b2 - a2b1)
Magnitude of cross product: |A × B| = |A| |B| sin(θ)
Cross product as determinant: A × B = det([i j k; a1 a2 a3; b1 b2 b3])

Theorems

Cross product theorem
Determinant theorem

Suitable Grade Level

Grades 11-12