Evaluate determinants

1
EXAMPLE 1
Evaluate determinants
Evaluate the determinant of the matrix.
SOLUTION
2
EXAMPLE 2
Find the area of a triangular region
3
EXAMPLE 2
Find the area of a triangular region
SOLUTION
757.5
The area of the region is about 758 square miles.
4
for Examples 1 and 2
GUIDED PRACTICE
Evaluate the determinant of the matrix.

3
2
1.
6
1
ANSWER
ANSWER
ANSWER
470
21
15
5
for Examples 1 and 2
GUIDED PRACTICE
4. Find the area of the triangle with vertices
A(5, 11), B(9, 2), and C(1, 3).