Question

已知a+b=2,ab=1.求a²+b²、(a-b)²的值

多谢

Answer 1

a+b=2,ab=1.求a²+b²、(a-b)²的值
a²+b²=（a+b）^2-2ab=2
(a-b)²=（a+b）^2-4ab=0

Answer 2

(a+b)2=a2+b2+2ab=a2+b2+2=4
a2+b2=2
（a-b)2=a2+b2-2ab=2-2=0