United States Multivariable Calculus - Vectors in Three Dimensions

In summary, the conversation discusses determining which points are co-linear and which point lies in between the other two points. The participants consider using the fact that PR is a multiple of PQ and suggest using the magnitude of PQ and PR to determine the placement of the third point. They also mention using a two-dimensional analogy to help solve the problem.
  • #1
GreenPrint
1,196
0

Homework Statement



See attachment

Homework Equations



The Attempt at a Solution



I'm not sure how to determine which points are co linear or which point lies in between the two. My book doesn't discuss how to do this at all.

but
PQ→ = <1,-1,2>, PR→ = <3,-3,6>
I believe I found these correctly but I'm not sure what to do from here. Thanks for any help anyone can provide.
 

Attachments

  • Question.PNG
    Question.PNG
    4.7 KB · Views: 369
Physics news on Phys.org
  • #2
GreenPrint said:

Homework Statement



See attachment

Homework Equations



The Attempt at a Solution



I'm not sure how to determine which points are co linear or which point lies in between the two. My book doesn't discuss how to do this at all.

but
PQ→ = <1,-1,2>, PR→ = <3,-3,6>
I believe I found these correctly but I'm not sure what to do from here. Thanks for any help anyone can provide.

PR is a multiple of PQ. Doesn't that tell you something?
 
  • #3
Mark44 said:
PR is a multiple of PQ. Doesn't that tell you something?

there parallel to each other but i don't know how that helps me answer the question
 
  • #4
GreenPrint said:
there parallel to each other but i don't know how that helps me answer the question

Imagine a similar setup in two dimensions. Suppose you are given three points, P, Q, and R in the x-y plane. Now suppose (as is the case in the original problem) that PQ is a multiple of PR. Try to make a graph of this scenario to convince yourself that the three points are colinear. Will this still be the case when we move up to three dimensions?
 
  • #5
hm i didn't think of it like that interesting
ok so they are indeed co linear then
can i find the magnitude of pq and pr and then just compare which one is smaller to determine if q lies in between p and r or if r lies between p and q?
 
  • #6
GreenPrint said:
hm i didn't think of it like that interesting
ok so they are indeed co linear then
can i find the magnitude of pq and pr and then just compare which one is smaller to determine if q lies in between p and r or if r lies between p and q?

Yes. You will compare distances to determine which point lies between the other two. Be sure to use the two dimensional analogy again if you get stuck (and keep it in mind for future problems :smile:).
 
  • #7
thanks for your help
 

1. What is multivariable calculus?

Multivariable calculus is a branch of mathematics that deals with functions of several variables. It extends the concepts of single-variable calculus to functions with multiple independent variables, allowing for the analysis of more complex systems and phenomena.

2. What are vectors in three dimensions?

Vectors in three dimensions are mathematical objects that have both magnitude (size) and direction. They are commonly represented as arrows in three-dimensional space and can be used to describe physical quantities such as velocity, acceleration, and force.

3. How are vectors represented in multivariable calculus?

In multivariable calculus, vectors are typically represented using coordinates, either in two or three dimensions. These coordinates can be used to calculate the magnitude and direction of the vector, as well as perform operations such as addition, subtraction, and scalar multiplication.

4. What is the significance of vectors in three dimensions?

Vectors in three dimensions are important in multivariable calculus because they allow for the analysis of systems and phenomena with multiple variables. They also play a crucial role in fields such as physics and engineering, where they are used to describe and model real-world situations.

5. How are vectors in three dimensions used in the United States?

Vectors in three dimensions are used extensively in various fields in the United States, including engineering, physics, computer graphics, and economics. They are also an important concept in many college-level courses, such as multivariable calculus and linear algebra.

Similar threads

  • Science and Math Textbooks
Replies
10
Views
2K
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus
Replies
14
Views
1K
  • Calculus and Beyond Homework Help
Replies
12
Views
1K
  • Calculus and Beyond Homework Help
Replies
16
Views
7K
  • Calculus and Beyond Homework Help
Replies
13
Views
2K
  • Calculus and Beyond Homework Help
Replies
6
Views
1K
Back
Top