SOLUTION: Determine whether each set of data is linear, quadratic, or neither using finite differences. X Y 1 -3 2 -2 3 2 4 9

X   Y  1st differences 2nd differences  
0  -1 
      -3-(-1)=-3+1=-2
1  -3                   1-(-2)=1+2=3
      -2-(-3)=-2+3= 1
2  -2                    4-1      =3
       2-(-2)= 2+2= 4
3   2                    7-4      =3 
        9-2  =      7
4   9

Since the SECOND differences are all the same -- that is, they 
are all 3's, the data is of a SECOND degree polynomial, which
means it is quadratic, and follows the quadratic or SECOND DEGREE 
equation



Edwin