% data for Chapter 2 Supplementary Exercises

ex = input('Exercise number (2,3,9,10)? ');

if ex==2 
   M = [3 -1 2 1;-6 3 -7 5] 
elseif ex==3
   A = [1 -2;-5 3;3 1] 
elseif ex==9
   A = [.8 .6;-.6 .8], v = [4;3]
   disp('Make sure you know how to find  a  and  b.') 
elseif ex==10
   A = [1/sqrt(5) 0 2/sqrt(5);0 1 0; -2/sqrt(5) 0 1/sqrt(5)], v = [2;3;4]
   disp('Make sure you know how to find  a  and  b.')
   disp(' ')
   disp('The entries in A contain the factor 1/sqrt(5).')
   disp('   Check this by computing  sqrt(5)*A.')
else
   disp('No data for this supplementary exercise, Chapter 2.')
end
