Questions: - You have learned how matrices model changing wetlands and the spread of a disease. What are some other contexts where matrices would be useful?
- How do you recognize a Markov matrix?
Transcript text: - You have learned how matrices model changing wetlands and the spread of a disease. What are some other contexts where matrices would be useful?
- How do you recognize a Markov matrix?
Solution
Solution Steps
Matrices are useful in various contexts such as computer graphics (for transformations and rotations), economics (for input-output models), and network theory (for representing graphs and connectivity).
A Markov matrix, also known as a stochastic matrix, is recognized by having all its entries be non-negative and each column summing to 1.
Step 1: Define the Matrix
We are given the matrix:
\[
\begin{bmatrix}
0.5 & 0.2 & 0.3 \\
0.5 & 0.8 & 0.7
\end{bmatrix}
\]
Step 2: Check Non-Negativity
We need to verify that all entries in the matrix are non-negative:
\[
0.5 \geq 0, \quad 0.2 \geq 0, \quad 0.3 \geq 0, \quad 0.5 \geq 0, \quad 0.8 \geq 0, \quad 0.7 \geq 0
\]
Since all entries are non-negative, this condition is satisfied.
Step 3: Check Column Sums
We need to check that the sum of each column is 1:
\[
\begin{aligned}
&0.5 + 0.5 = 1, \\
&0.2 + 0.8 = 1, \\
&0.3 + 0.7 = 1
\end{aligned}
\]
Since the sum of each column is 1, this condition is also satisfied.
Final Answer
The given matrix is a Markov matrix because it satisfies both conditions: all entries are non-negative, and the sum of each column is 1.