Math Problem Statement

Express the vector w as a linear combination of the vectors v₁ and v₂, or determine if it cannot be expressed as such.

Solution

The problem asks you to express the vector w as a linear combination of the vectors v₁ and v₂.

Given: w=[8118],v1=[111],v2=[211]\mathbf{w} = \begin{bmatrix} -8 \\ 11 \\ 8 \end{bmatrix}, \quad \mathbf{v_1} = \begin{bmatrix} -1 \\ 1 \\ 1 \end{bmatrix}, \quad \mathbf{v_2} = \begin{bmatrix} 2 \\ 1 \\ 1 \end{bmatrix}

We need to find scalars c1c_1 and c2c_2 such that: w=c1v1+c2v2\mathbf{w} = c_1 \mathbf{v_1} + c_2 \mathbf{v_2} This can be written as the system of equations: [8118]=c1[111]+c2[211]\begin{bmatrix} -8 \\ 11 \\ 8 \end{bmatrix} = c_1 \begin{bmatrix} -1 \\ 1 \\ 1 \end{bmatrix} + c_2 \begin{bmatrix} 2 \\ 1 \\ 1 \end{bmatrix} This gives the following system of equations:

  1. c1+2c2=8-c_1 + 2c_2 = -8
  2. c1+c2=11c_1 + c_2 = 11
  3. c1+c2=8c_1 + c_2 = 8

However, notice that equations 2 and 3 are contradictory, because both cannot be true simultaneously. This means there is no solution for c1c_1 and c2c_2 that satisfies all three equations.

Therefore, the vector w cannot be expressed as a linear combination of v₁ and v₂, and the answer is DNE (Does Not Exist).

Would you like further details or have any questions about this? Here are 5 related questions for further exploration:

  1. How do you solve a system of equations for linear combinations?
  2. What does it mean if a vector cannot be expressed as a linear combination of other vectors?
  3. What is the geometric interpretation of a linear combination in 3D space?
  4. How would you check if a set of vectors is linearly independent?
  5. What is the rank of a matrix, and how is it related to linear combinations?

Tip: When equations in a system contradict each other, it typically means the vectors are linearly independent and the combination does not exist.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Vector Spaces
Systems of Equations

Formulas

w = c₁ * v₁ + c₂ * v₂
System of linear equations

Theorems

Linear Combination Theorem
Inconsistency in Linear Systems

Suitable Grade Level

Undergraduate - Early