解：原式=X�0�5+2XY+Y�0�5 =(X+Y)�0�5 把X=√3 + 1，Y=√3 - 1代入，得 (√3 + 1 + √3 - 1)�0�5 =(2√3)�0�5 =12
X=2 y=2X的平方+2XY+Y的平方 =(X+Y)�0�5=（2+2）�0�5=16
x*x+2xy+y*y=(x+y)*(x+y)=(2倍根号3)*(2倍根号3)=12
=12
