Tugas Matek Pertemuan 11

TUGAS 11-02 DETERMINAN DAN MATRIK INVERS 1.

Hitung determinan dari matrik: 2  3 P =  1  1 

1 2 3 1

1 2 2 3

3  1 2  2 

2. Carilah matrik invers dari matrik: 3 0 1   Q =  1 2 0 0 3 1   Menggunakan metode Adjoin.

JAWABAN 1.

Determinan = 2*2*2*2 + 1*2*2*1 + 1*1*1*1 + 3*3*3*3 – 1*3*2*3 – 1*2*1*2 – 3*1*3*2 – 2*1*2*1 = 16 + 4 + 1 + 81 – 18 – 4 – 18 – 4 = 58 ↔ JAWABANNYA

2. M11 =

M12 =

M13 =

M21 =

M22 =

M23 =

M31 =

M32 =

M33 =

A11 = (-1)2(2) A12 = (-1)3(1) A13 = (-1)4(3) A21 = (-1)3(-3) A22 = (-1)4(3)

=2 = -1 =3 =3 =3

A23 = (-1)5(9) A31 = (-1)4(-2) A32 = (-1)5(-1) A33 = (-1)6(6)

= -9 = -2 =1 =6

Determinan A = 3*2*1 + 0*0*0 + 1*3*1 – 0*2*1 – 1*0*1 – 3*3*0 =6+0+3–0–0–0 =9 A-1 = Adj.A / determinan A

A-1 =

↔ JAWABANNYA