（1）當(dāng)a=4,b=2時(shí)
a^2-2ab+b^2 =16-16+4 =4
(a-b)^2 = (4-2)^2= 4
兩個(gè)代數(shù)式的值相同.
當(dāng)a=1/2,b=1/4時(shí)
a^2-2ab+b^2 =1/4-1/4+1/16 =1/16
(a-b)^2 =(1/2-1/4)^2 =(1/4)^2=1/16
兩個(gè)代數(shù)式的值相同.
（3）由上述結(jié)論發(fā)現(xiàn)a^2-2ab+b^2 =(a-b)^2
當(dāng)a=1001/1000,b=501/1000時(shí)
a^2-2ab+b^2 =(a-b)^2 ＝（1001/1000-501/1000）^2 = (1/2)^2 =1/4