Exam Finished~

細薯

Later i will post the questions and discuss with you all~~
please help me also~~
thx a lot~~^^

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New Trend A.Maths. Volume One
Chapter 1 ,P.14 ,Ex.1B,Q.16

16.(a)IF a,b and c are real numbers and not all equal ,prove that the quadratic equation
(c-a)x^2 - 2(a-b)x +(b-c) = 0
has unequal real roots.

    (b)If a = 1, b = 3,find the discriminant of the equation in (a).Hence find the range of values of c so that the equation has unequal real roots.
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[ Last edited by smallpotato226 on 2005-3-10 at 05:50 PM ]

抹茶可樂

maybe no simple steps can be solved

lamsir

Originally posted by 落雷 at 2005-2-8 09:15 PM:
maybe no simple steps can be solved

why??it is the question in theFIRSTchapters!!
it is a difficult job??OMG.......

kokoro

Originally posted by lamsir at 2005-2-10 04:35 PM:

why??it is the question in theFIRSTchapters!!
it is a difficult job??OMG.......

It may not be a difficult job, but it is difficult to present.
OR can you show your steps/presentation :)?

lamsir

Originally posted by kokoro at 2005-2-10 06:29 PM:

It may not be a difficult job, but it is difficult to present.
OR can you show your steps/presentation :)?

in fact,i don't know how to do,then how could i know the steps...

oscar

我想你要自己撞答案...

suny

係唔係二元一次方程?
係唔係咁.....


┌x^2 + ax + 12 =0   (i)
└x^2 + 9x + a =0     (ii)

從(i),
x^2+ax+12=0
      x^2+ax= -12
        x(x+a)= -12
            x+a= -12/x
                a= (-12/x)-x   (iii)

(iii)代入(ii),可得
x^2+9x+(-12/x)-x=0
     x^2+8x-(12/x)=0
      x(x+8) -(12/x)=0
                 x(x+8)=12/x
                     x+8=12/x^2
                         x=(12/x^2)-8


跟住........唔係好掂[E-Swe]

kokoro

a同b係2題來的…
諗係好易 XD
Present就煩 XD

細薯

用D=b^2-4ac 都ng得.........><
========================================
呀!我諗到D野丫!
掉轉泥calculate 都得wor~~

TRY:
(a)
since x must be integral solutions,
therefore,sub. x = 1,2,3 into the equation satisfy the equation

x^2 + ax + 12 =0

1+a+12=0    =>   a=-13

4+2a+12=0  =>  a=-8

9+3a+12=0   => a=-7

etc.

(Give up to three answers if necessary.)

ok ma??

1)G.Maths.
In each of the following equations,what integral value(s) should a take so that the equation will have integral solutions?
(Give up to three answers if necessary.)
(a)x^2 + ax + 12 =0
(b)x^2 + 9x + a =0
(i have answer,plx teach me the steps~~thx~~)

[ Last edited by smallpotato226 on 2005-2-16 at 10:13 AM ]

細薯

one A.Maths. question in #1,plx help~~