n = 7
t = [ -1 0 1 2 2.5 3.1 6]'
y = [1 1 2 3 4 5 3]'
einsen = ones(n,1)
A = [ einsen, t, t.^2 ]
Aty = A' * y
AtA = A' * A
x = mldivide( AtA, Aty )
gerade = A * x

tt = linspace( t(1) , t(n), 30 )
for i = 1 : 3
    x_neu(i) = x( (3+1) - i )
    
end
yy = polyval( x_neu, tt )


plot( t, y , 'o' , tt, yy)
