Week 6

Question 1

Inversion alogrithm?

Answer 1

(A l I ) , and row elementary operations until A=RREF

then I after these operations is inverse

Question 2

If det lAl does not equal 0?

Answer 2

• Matrix is invertible
  -Has a unique solution

Question 3

Adjoint method?

Answer 3

-normaly way to calculate inverse (a-level)

Question 4

Cramer’s rule?

Answer 4

x= l b c2 c3l / lAl

y= l c1 b c3l / lAl

z= l c1 c2 bl / lAl

Question 5

l 3 A l ? for square matrix

Answer 5

3^n l A l

Question 6

l (2A)^-1 l ? for square matrix

Answer 6

1/ l 2 A l = 1/ 2^n l A l

Question 7

l 2 A^-1 l ? for square matrix

Answer 7

2^n / l A l