Machine-translated by Google. Questions are authored in English.
Top

Discussion

Let \(T : \mathbf{R}^{3} \to \mathbf{R}^{2}\) be a linear map such that :

\[ T\begin{bmatrix} 1 \\ 0 \\ 0 \end{bmatrix} = \begin{bmatrix} 1 \\ 0 \end{bmatrix}, \quad T\begin{bmatrix} 0 \\ 1 \\ 0 \end{bmatrix} = \begin{bmatrix} 0 \\ 1 \end{bmatrix} \]

and

\[ T\begin{bmatrix} 0 \\ 1 \\ 1 \end{bmatrix} = \begin{bmatrix} 1 \\ 1 \end{bmatrix}. \]

Then \(T\begin{bmatrix} 1 \\ 1 \\ 1 \end{bmatrix} =\)

  • A.\(\begin{bmatrix} 2 \\ 1 \end{bmatrix}\)
  • B.\(\begin{bmatrix} 1 \\ 1 \end{bmatrix}\)
  • C.\(\begin{bmatrix} -1 \\ 2 \end{bmatrix}\)
  • D.\(\begin{bmatrix} 2 \\ 2 \end{bmatrix}\)

Answer: A

\(T(1, 1, 1)\) is \(\begin{bmatrix} 2 \\ 1 \end{bmatrix}\).

Write the vector as a combination of the vectors whose images are given:

\[ (1, 1, 1) = (1, 0, 0) + (0, 1, 1) \]

By linearity,

\[ T(1, 1, 1) = (1, 0) + (1, 1) = (2, 1) \]

The information \(T(0, 1, 0) = (0, 1)\) is not needed. Adding all three given images gives (2, 2), which is the trap in option D; (1, 1) is the image of (0, 1, 1) alone.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.