x=[0.6-cos(0.6) 0.7-cos(0.7) 0.8-cos(0.8) 0.9-cos(0.9)]
x =

  -0.2253356149096784  -0.0648421872844885   0.1032932906528347   0.2783900317293356

>> fx=[0.6 0.7 0.8 0.9]
fx =

   0.600000000000000   0.700000000000000   0.800000000000000   0.900000000000000

>> n=4
n =  4
>> for k=1:n
Q(1:n,1)=fx;
for i=2:n
for j=2:i
Q(i,j)=((0-x(i-j+1))*Q(i,j-1)-(0-x(i))*Q(i-1,j-1))/(x(i)-x(i-j+1));
end
end
end
>> Q
Q =

   0.600000000000000   0.000000000000000   0.000000000000000   0.000000000000000
   0.700000000000000   0.740401771115462   0.000000000000000   0.000000000000000
   0.800000000000000   0.738565440250903   0.739142628241725   0.000000000000000
   0.900000000000000   0.741007873694402   0.739026855928103   0.739090838888426

>> cos(Q(4,4))
ans =  0.739081289792984