Use the matrix capabilities of a graphing utility to find the determinant of the matrix $\left[ \begin{array} { c c c }
3 & 4.5 & 1.5 \
0 & 7.5 & - 3 \
0 & 0 & - 3
\end{array} \right]$ .
A) $- 67.5$
B) $- 16.875$
C) $0$
D) $101.25$
E) $- 6.75$

Question

Use the matrix capabilities of a graphing utility to find the determinant of the matrix $\left[ \begin{array} { c c c } 
3 & 4.5 & 1.5 \
0 & 7.5 & - 3 \
0 & 0 & - 3
\end{array} \right]$ .
A) $- 67.5$
B) $- 16.875$
C) $0$
D) $101.25$
E) $- 6.75$

Quizplus · Accepted Answer

The determinant of a triangular matrix (all zeros below or above the main diagonal) is the product of its diagonal elements. Thus, $3 \times 7.5 \times (-3) = -67.5$.

Use the Matrix Capabilities of a Graphing Utility to Find [34.51.507.5−300−3]\left[ \begin{array} { c c c } 3 & 4.5 & 1.5 \\0 & 7.5 & - 3 \\0 & 0 & - 3\end{array} \right]​300​4.57.50​1.5−3−3​​

Use the Matrix Capabilities of a Graphing Utility to Find $\left[ \begin{array} { c c c } 3 & 4.5 & 1.5 \\0 & 7.5 & - 3 \\0 & 0 & - 3\end{array} \right]$