solving an equation using linsolve...............

In the following:

s =

     2     3
     3     4

t =

     1
     2

[p q]=linsolve(s,t)

p =

    2.0000
   -1.0000

q =

    0.0204

How to find out q manually........

Answer 1

[Azzi Abdelmalek]

I am not sure what you mean by manually:

 q=rcond(s)

[Tankeswar Kumar]

My question is how q is calculated mathematically.....Manually means mathematically solve..............

[Azzi Abdelmalek]

1/(norm(s,1)*norm(inv(s),1))

[Azzi Abdelmalek]

In your case

norm(s,1)=max(2+3,3+4)=7
inv(s)=
  -4     3
   3    -2
norm(inv(s),1)=max(abs(-4)+3,3+abs(-2))=7

Then

rcond(s)=1/(7*7)=0.204