請指教........

x^2 - 3x/2 + p=0 (?)

discriminant = b^2 - 4ac >=0

(3/2)^2 - 4(1)(p) >=0
9/4-4p>=0
9/4>=4p
p<=9/16

2006-12-01 18:22:44 補充：
應該係b^2-4ac=0(3/2)^2 - 4(1)(p)=09/4-4p=09/4=4pp=9/16

x^2 - (3/2)x + p
= x^2 - (2)(3/4)x + p
其數式是完全平方的話，則數式會 = (x - 開方p)^2

由於已知 (a-b)^2 = a^2-2(a)(b)+b^2

所以 p = (3/4)^2
於是 p = 9/16