How do I solve the dot and cross product of 3i and jxk?

In summary, the dot product is a mathematical operation that returns a scalar quantity and measures the similarity or projection of one vector onto another, while the cross product returns a vector quantity and measures the perpendicularity or rotation of one vector from another. The dot product is calculated by multiplying the corresponding components of two vectors and summing the results, while the cross product is calculated by taking the determinant of a 3x3 matrix formed by the two vectors and the unit vectors. The geometric interpretation of the dot product is the product of the magnitude of one vector and the length of the projection of the other vector onto the first, while the cross product is the area of the parallelogram formed by the two vectors. Both can be visualized using specific
  • #1
jdawg
367
2

Homework Statement



The value of 3i(dot)(jxk)

Homework Equations





The Attempt at a Solution


I know the answer is 3, but could someone please explain how to work this problem?
 
Physics news on Phys.org
  • #2
Start by evaluating the cross product. You can go through the matrix and determinants to solve for it, but j x k can be evaluated by just thinking about it -- what vector is perpendicular to both j and k, and follows the right-hand rule?

Then you can evaluate the dot product by component.
 
  • #3
Ohh! Thank you so much, I get it now :)
 

Related to How do I solve the dot and cross product of 3i and jxk?

1. What is the difference between the dot and cross product?

The dot product is a mathematical operation that takes two vectors and returns a scalar quantity, while the cross product takes two vectors and returns a vector quantity. The dot product measures the similarity or projection of one vector onto another, while the cross product measures the perpendicularity or rotation of one vector from another.

2. How do you calculate the dot product of two vectors?

The dot product of two vectors, A and B, is calculated by multiplying the corresponding components of the vectors and then summing the results. In other words, A ∙ B = AxBx + AyBy + AzBz.

3. How do you calculate the cross product of two vectors?

The cross product of two vectors, A and B, is calculated by taking the determinant of a 3x3 matrix formed by the two vectors and the unit vectors i, j, and k. In other words, A x B = i(AyBz - AzBy) - j(AxBz - AzBx) + k(AxBx - AyBx).

4. What is the geometric interpretation of the dot product?

The dot product can be interpreted geometrically as the product of the magnitude of one vector and the length of the projection of the other vector onto the first. This can be visualized using the formula A ∙ B = |A||B|cosθ, where θ is the angle between the two vectors.

5. What is the geometric interpretation of the cross product?

The cross product can be interpreted geometrically as the area of the parallelogram formed by the two vectors. This can be visualized using the formula |A x B| = |A||B|sinθ, where θ is the angle between the two vectors.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
785
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
983
  • Precalculus Mathematics Homework Help
Replies
5
Views
684
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
739
  • Calculus and Beyond Homework Help
Replies
6
Views
923
  • Calculus and Beyond Homework Help
Replies
19
Views
2K
Back
Top