(%i2) "Cornelsen, S. 207, Übung 2"$ (%i3) A1: matrix([2.0,3.0,-1.0],[4.0,-2.0,1.0]); [ 2.0 3.0 - 1.0 ] (%o3) [ ] [ 4.0 - 2.0 1.0 ] (%i4) B1: matrix([1.0,2.0,-2.0,3.0],[-1.0,3.0,2.0,0.0],[2.0,0.0,4.0,1.0]); [ 1.0 2.0 - 2.0 3.0 ] [ ] (%o4) [ - 1.0 3.0 2.0 0.0 ] [ ] [ 2.0 0.0 4.0 1.0 ] (%i5) A1 . B1; [ - 3.0 13.0 - 2.0 5.0 ] (%o5) [ ] [ 8.0 2.0 - 8.0 13.0 ] (%i6) B1 . A1; MULTIPLYMATRICES: attempt to multiply nonconformable matrices. -- an error. Folgerung? (%i7) A2: matrix([1.0,2.0,0.0],[2.0,3.0,0.0],[3.0,4.0,1.0]); [ 1.0 2.0 0.0 ] [ ] (%o7) [ 2.0 3.0 0.0 ] [ ] [ 3.0 4.0 1.0 ] (%i8) B2: matrix([-3.0,2.0,0.0],[2.0,-1.0,0.0],[1.0,-2.0,1.0]); [ - 3.0 2.0 0.0 ] [ ] (%o8) [ 2.0 - 1.0 0.0 ] [ ] [ 1.0 - 2.0 1.0 ] (%i9) A2 . B2; [ 1.0 0.0 0.0 ] [ ] (%o9) [ 0.0 1.0 0.0 ] [ ] [ 0.0 0.0 1.0 ] (%i10) B2 . A2; [ 1.0 0.0 0.0 ] [ ] (%o10) [ 0.0 1.0 0.0 ] [ ] [ 0.0 0.0 1.0 ] (%i11) "Folgerung aus A2 . B2 = E = B2 . A2 ?"$ (%i12) "Cornelsen, S. 209, Nr. 8"$ (%i13) "Antwort: 4 x Falsch (!)"$ (%i14) "Cornelsen, S. 209, Nr. 7"$ Anleitung: Stelle eine 'Gewinnmatrix' als 4x1-Matrix auf, und ermittle den Gewinn für jede Filiale durch Matrizenmultiplikation. Beachte: Als Ergebnis muss eine Zahl herauskommen! (Warum?) Ergebnis: 1: 1490 EUR; 2: 1520 EUR; 3: 480 EUR; 4: 2010 EUR