我用这组数据做了一个一元线性回归和二次方程，可是为什么求出来的拟合函数是一样的？


一元线性回归Coefficients
Unstandardized Coefficients Standardized Coefficients t Sig.
B Std. Error Beta
VAR00001 3.233 .137 .976 23.686 .000
(Constant) -6196.242 272.258 -22.759 .000




二次方程 Coefficients
Unstandardized Coefficients Standardized Coefficients t Sig.
B Std. Error Beta
VAR00001 3.233 .137 .976 23.686 .000
(Constant) -6196.242 272.258 -22.759 .000


Excluded Terms
Beta In t Sig. Partial Correlation Minimum Tolerance
VAR00001 ** 2(a) -43.397 -4.943 .000 -.689 .000
a The tolerance limit for entering variables is reached.
请问VAR00001**2(a)表示什么？是与x^2有关的系数吗？