In order to reduce food waste, we should plan our food consumption.

I think his plan is putting the cart before the horse.

I think he put the cart before the horse because he started taking action before making a detailed plan.

The marquis was proud of his position.

What is this powder?

A positive-definite matrix is an important concept in linear algebra.

A positive-semidefinite matrix is one of the important concepts in linear algebra.

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.