06.08.2013 Views

Web skærmformat. - Aarhus Universitet

Web skærmformat. - Aarhus Universitet

Web skærmformat. - Aarhus Universitet

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

V. Matricer – 1. Vektorer og matricer 378<br />

Eksempel<br />

Rækkesum ⎛<br />

Søjlesum<br />

⎜<br />

⎝<br />

a11 ... a1n<br />

. aij<br />

.<br />

am1 ... amn<br />

⎜<br />

1, ..., 1 ⎝<br />

⎞ ⎛ ⎞ ⎛<br />

⎞<br />

1 a11 + · · · + a1n<br />

⎟ ⎜ .<br />

⎠ ⎝ .<br />

⎟ ⎜<br />

. ⎠ =<br />

.<br />

⎝ .<br />

⎟<br />

. ⎠<br />

1 am1 + · · · + amn<br />

⎛<br />

a11 ... a1n<br />

. aij<br />

.<br />

am1 ... amn<br />

⎞<br />

⎟<br />

⎠<br />

= <br />

a11 + · · · + am1, ..., a1n + · · · + amn<br />

1.22. Vigtigste regneregel ☞ [LA] 2 Matricer<br />

Sætning 1 (Associativ lov)<br />

Matrix multiplikation er associativ. Givet A en m × n-matrix, B en n × p-matrix og C en p × qmatrix,<br />

så er følgende to m × q-matricer ens.<br />

Bevis<br />

(AB)C = A(BC)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!