Find a QR factorization of A. Answers should be in exact form (i.e., do not use a calculator to get a
decimal approximation).
$$A = \begin{bmatrix} 1 & 1 & -1 \\ 1 & 0 & -2 \\ 0 & 1 & 0 \\ 1 & 1 & -1 \end{bmatrix}$$
A = [(,,,),(,,,), (,,,)]
Note: Since there are an infinite number of QR factorizations, you must enter both Q and R for
the question to determine whether your answer is correct.