Which of these matrices are triangular matricesSolutionA squ

Which of these matrices are triangular matrices?

Solution

A square matrix is called lower triangular if all the entries above the main diagonal are zero. Similarly, a square matrix is called upper triangular if all the entries below the main diagonal are zero. A triangular matrix is one that is either lower triangular or upper triangular. A matrix that is both upper and lower triangular is called a diagonal matrix.

So, here in the given matrix we observe that neither all the entries above the main diagonal are zero nor the entries below the main digonal are zero.

Therefore, the given matrix is not a traingular matrix.