Form3 maths急問,聽日test牙!!!!岩哂10000好友元 [復制鏈接]

impossible 203

真係唔識

引用第13樓Skyline於2006-10-26 22:23發表的“”:
question4
2既x+3次方+2既x次方 = 9/16
2^x * 2^3 +2^x= 9/16
2^x*8+2^x= 9/16
.......

THX 2500聽日過

引用第16樓mach仔於2006-10-26 22:24發表的“”:
真係唔識 [表情]

我d數都係f.3,我平時maths都ok,but真係唔識

x^2/x^4+x^2+1

係 x^2/x^4+x^2 +1?

Q3

2^4X = 203

冇可能喎...

引用第20樓mach仔於2006-10-26 22:33發表的“”:
Q3
2^4X = 203
冇可能喎...

係囉...計唔到架喎

a )Expand (x+x^-1)^2
b )given that x   + x^-1   = 5 ,determine x^2 + x^-2


A) =x^2+2(x)(x^-1)+x^-2
=x^2+(x^-2)+2

b)x+x^-1=5
TAKE SQUARE BOTH SIDE
x^2+(x^-2)+2=25
x^2+(x^-2)=25-2=23

引用第20樓mach仔於2006-10-26 22:33發表的“”:
Q3
2^4X = 203
冇可能喎...

引用第15樓handsome 仔於2006-10-26 22:24發表的“”:
impossible 203

引用第21樓calvin02於2006-10-26 22:33發表的“”:
係囉...計唔到架喎

個答案係3/2

q1
x^2+2+x-2
b.(x+x^-1)^2=x^2+2+x^-2
25=x^2+2+x^-2
x^2+x^-2=23

a )Expand (x+x^-1)^2
=(x+a/x)^2
=x^2+2+1/x^2
b.(x+x^-1)^2=x^2+2+x^-2
25=x^2+2+x^-2
x^2+x^-2=23

引用第22樓SuN FoReVeR於2006-10-26 22:34發表的“”:
a )Expand (x+x^-1)^2
b )given that x   + x^-1   = 5 ,determine x^2 + x^-2
A) =x^2+2(x)(x^-1)+x^-2
=x^2+(x^-2)+2
b)x+x^-1=5
TAKE SQUARE BOTH SIDE
x^2+(x^-2)+2=25
x^2+(x^-2)=25-2=23
.......

點黎架????

引用第24樓abbrian2005於2006-10-26 22:36發表的“”:
個答案係3/2 [表情]

引用第26樓calvin02於2006-10-26 22:36發表的“”:
a )Expand (x+x^-1)^2
=(x+a/x)^2
=x^2+2+1/x^2
b.(x+x^-1)^2=x^2+2+x^-2
25=x^2+2+x^-2
.......

邊度有個a出黎?