Find the standard matrix for the linear transformation T: R2 R² that reflects points about the origin 3π and then rotates points about the origin by radians. 4

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Chapter2: Second-order Linear Odes
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**Problem Statement:**

Find the standard matrix for the linear transformation \( T: \mathbb{R}^2 \to \mathbb{R}^2 \) that reflects points about the origin and then rotates points about the origin by \(\frac{3\pi}{4}\) radians.

**Solution Approach:**

To solve this problem, two key operations are involved:

1. **Reflection about the Origin:**
   - The matrix for reflecting points about the origin in \(\mathbb{R}^2\) is:
     \[
     R = \begin{bmatrix} -1 & 0 \\ 0 & -1 \end{bmatrix}
     \]

2. **Rotation by \(\frac{3\pi}{4}\) Radians:**
   - The matrix for rotating points about the origin by an angle \(\theta\) is:
     \[
     M(\theta) = \begin{bmatrix} \cos(\theta) & -\sin(\theta) \\ \sin(\theta) & \cos(\theta) \end{bmatrix}
     \]
   - Here, \(\theta = \frac{3\pi}{4}\), so:
     \[
     M\left(\frac{3\pi}{4}\right) = \begin{bmatrix} \cos\left(\frac{3\pi}{4}\right) & -\sin\left(\frac{3\pi}{4}\right) \\ \sin\left(\frac{3\pi}{4}\right) & \cos\left(\frac{3\pi}{4}\right) \end{bmatrix} = \begin{bmatrix} -\frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}{2} \\ \frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}{2} \end{bmatrix}
     \]

**Standard Matrix Calculation:**

The standard matrix for the transformation \( T \) is obtained by multiplying the matrices for reflection and rotation: \( T = M\left(\frac{3\pi}{4}\right) \times R \).

Thus, the standard matrix for \( T \) is:
\[
T = \begin{bmatrix} -\frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}
Transcribed Image Text:**Problem Statement:** Find the standard matrix for the linear transformation \( T: \mathbb{R}^2 \to \mathbb{R}^2 \) that reflects points about the origin and then rotates points about the origin by \(\frac{3\pi}{4}\) radians. **Solution Approach:** To solve this problem, two key operations are involved: 1. **Reflection about the Origin:** - The matrix for reflecting points about the origin in \(\mathbb{R}^2\) is: \[ R = \begin{bmatrix} -1 & 0 \\ 0 & -1 \end{bmatrix} \] 2. **Rotation by \(\frac{3\pi}{4}\) Radians:** - The matrix for rotating points about the origin by an angle \(\theta\) is: \[ M(\theta) = \begin{bmatrix} \cos(\theta) & -\sin(\theta) \\ \sin(\theta) & \cos(\theta) \end{bmatrix} \] - Here, \(\theta = \frac{3\pi}{4}\), so: \[ M\left(\frac{3\pi}{4}\right) = \begin{bmatrix} \cos\left(\frac{3\pi}{4}\right) & -\sin\left(\frac{3\pi}{4}\right) \\ \sin\left(\frac{3\pi}{4}\right) & \cos\left(\frac{3\pi}{4}\right) \end{bmatrix} = \begin{bmatrix} -\frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}{2} \\ \frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}{2} \end{bmatrix} \] **Standard Matrix Calculation:** The standard matrix for the transformation \( T \) is obtained by multiplying the matrices for reflection and rotation: \( T = M\left(\frac{3\pi}{4}\right) \times R \). Thus, the standard matrix for \( T \) is: \[ T = \begin{bmatrix} -\frac{\sqrt{2}}{2} & -\frac{\sqrt{2}}
Suppose \( T: \mathbb{R}^3 \to \mathbb{R}^2 \) is a linear transformation with \( T(x_1, x_2, x_3) = (-10x_2, -5x_1 + 11x_2 - 7x_3) \). Find the (standard) matrix \( A \) such that \( T(\mathbf{x}) = A\mathbf{x} \).

\[
\begin{bmatrix}
    &   &   \\
    &   &   \\
\end{bmatrix}
\]
Transcribed Image Text:Suppose \( T: \mathbb{R}^3 \to \mathbb{R}^2 \) is a linear transformation with \( T(x_1, x_2, x_3) = (-10x_2, -5x_1 + 11x_2 - 7x_3) \). Find the (standard) matrix \( A \) such that \( T(\mathbf{x}) = A\mathbf{x} \). \[ \begin{bmatrix} & & \\ & & \\ \end{bmatrix} \]
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