回复：Math is not riddle

f(0)=-128/9, as you did. It is my carelessness....

I think pfollowing is the explanation: a(x-5)^2+b,...a=-b/9...

ff=-b/9(-b/9(x-5)^2+b-5)^2+b=0,only b=2,x=5 is unique real root, b=8,has three 3 roots,not good.key point b-5 <0. Here is not riddle.

所有跟帖： 

• Why make stupid calcul when -15少- ♂ (815 bytes) () 07/15/2011 postreply 17:33:47

• You totally misunderstanding me, f(x)=a(X-5)^2+b,why b=2? you te -jinjing- ♀ (37 bytes) () 07/15/2011 postreply 18:04:50

• you tell me,please,not 8. -jinjing- ♀ (0 bytes) () 07/15/2011 postreply 18:07:08

• Ms. Kang has explained, her explanation is not as clear as you d -15少- ♂ (461 bytes) () 07/16/2011 postreply 06:30:03

• Why f(8)=0?Cs we use a Thm, It is unknow for most people here. -jinjing- ♀ (493 bytes) () 07/16/2011 postreply 08:19:30

• You like calcul -15少- ♂ (329 bytes) () 07/16/2011 postreply 09:10:20

• 回复：You totally misunderstanding me, f(x)=a(X-5)^2+b,why b=2? you -15少- ♂ (1365 bytes) () 07/16/2011 postreply 06:09:01