Question

Matrix $A=\left[\begin{array}{cccc}2& 0& 1& 1\\ 0& -1& -2& 3\\ 0& 0& 1& 4\\ 0& 0& 0& 2\end{array}\right]$ is a ___ matrix

• A. Unit Matrix
• B. Rectangular Matrix
• C. Upper triangular matrix
• D. Lower triangular matrix

Answer 1

The correct option is C

Upper triangular matrix

A square matrix is called upper triangular matrix if all the elements below the main diagonal are zero. Hence the given matrix is an upper triangular matrix.