### Episode 06b (7:10):

Why Triangle x Triangle = Rectangle Works

#### Summary:

We explain why $\mathbf{L}\mathbf{U}$ factorization works for any matrix $\mathbf{A}$ of any shape. Elimination matrices are the key, and we find why the product of their inverses is always simple.

#### Best dined upon by 2016/09/14

#### Duration: 7:10