In linear algebra, triangular matrices play a very important role.

A skew-symmetric matrix has the characteristic that its transpose matrix is the inverse of the original matrix.

The calculation of this transposed matrix is a bit complicated.

This square matrix has the same number of rows and columns.

A diagonal matrix is a matrix in which all elements outside the main diagonal are zero.

A lower triangular matrix is a matrix where all the elements below the main diagonal are zero.

The sales of this product are very good.

He was deeply grieving the death of his family.

In linear algebra, the upper triangular matrix plays a very important role.

He said, 'Even if you die in the evening, it's okay if you ask the way in the morning,' teaching me the importance of living each day to the fullest.