### 15.3.3 QR decomposition (for TI compatibility)

The QR command finds the QR decomposition of a matrix.

- QR takes three arguments:
  - A, a square matrix.
  - q and r, two variable names.
- QR(A,q,r) returns the matrix R from the QR decomposition of A, and assigns the matrices Q and R to the variables q and r.

#### Example

QR([[3,5],[4,5]],Q,R)

⎡
⎢
⎣

5 | 7
0 | 1

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⎥
⎦

The result is the matrix R. To obtain Q:

Q

⎡
⎢
⎢
⎢
⎢
⎢
⎢
⎢
⎣

3
5

4
5

4
5

−

3
5

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⎥
⎥
⎥
⎥
⎥
⎥
⎥
⎦