Results 1 to 7 of 7

Thread: Find (alpha), (beta), and (gamma) s.t Vector D = (alpha)VA + (beta)VB + (gamma)VC

  1. #1

    Find (alpha), (beta), and (gamma) s.t Vector D = (alpha)VA + (beta)VB + (gamma)VC

    I'm working on an exercise, not sure if I am posting in the right place though... first time on this website

    Vector A = 3i - 2j + k

    Vector B = -2i + 5j + 4k

    Vector C = -4i + j + -2k

    Vector D = 2i - j + 4k

    determine (alpha), (beta), and (gamma) such that Vector D = (alpha)VA + (beta)VB + (gamma)VC

    I have no idea where to start on this, is should I be doing scalar projections or something with unit vectors? Have I missed something obvious??
    I got really lost and none of my answers came out right (I know the solution, just not how to get to it)

  2. #2
    Elite Member
    Join Date
    Jun 2007
    Posts
    17,625
    Quote Originally Posted by ania1224 View Post
    I'm working on an exercise, not sure if I am posting in the right place though... first time on this website

    Vector A = 3i - 2j + k

    Vector B = -2i + 5j + 4k

    Vector C = -4i + j + -2k

    Vector D = 2i - j + 4k

    determine (alpha), (beta), and (gamma) such that Vector D = (alpha)VA + (beta)VB + (gamma)VC

    I have no idea where to start on this, is should I be doing scalar projections or something with unit vectors? Have I missed something obvious??
    I got really lost and none of my answers came out right (I know the solution, just not how to get to it)
    What are those?
    “... mathematics is only the art of saying the same thing in different words” - B. Russell

  3. #3

    clarification

    Vector A = VA

    Vector B = VB

    Vector C = VC

  4. #4

    they are

    Quote Originally Posted by Subhotosh Khan View Post
    What are those?
    they are Vector A, Vector B, and Vector C

  5. #5
    Junior Member
    Join Date
    Jan 2018
    Location
    Boston
    Posts
    162
    You should review the text book: What is a vector? What are i, j, k? How do we add vectors? How do we multiply a vector by a number?

  6. #6
    Elite Member
    Join Date
    Jun 2007
    Posts
    17,625
    Quote Originally Posted by ania1224 View Post
    I'm working on an exercise, not sure if I am posting in the right place though... first time on this website

    Vector A = 3i - 2j + k

    Vector B = -2i + 5j + 4k

    Vector C = -4i + j + -2k

    Vector D = 2i - j + 4k

    determine (alpha), (beta), and (gamma) such that Vector D = (alpha)VA + (beta)VB + (gamma)VC

    I have no idea where to start on this, is should I be doing scalar projections or something with unit vectors? Have I missed something obvious??
    I got really lost and none of my answers came out right (I know the solution, just not how to get to it)
    What would you get for:

    (Vector A) + (Vector B) + (Vector C) = ?
    “... mathematics is only the art of saying the same thing in different words” - B. Russell

  7. #7

    adding them

    Quote Originally Posted by Subhotosh Khan View Post
    What would you get for:

    (Vector A) + (Vector B) + (Vector C) = ?
    Adding them together gets me -3i + 4j + 3k, but I'm not sure how that helps me decide how much to multiply each vector so that they equal Vector D

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •