f4mathssssssssssssss urgen

one root of the quadratic equation 3x^2 +a=0 is 2
find the other Root

Sub 2 into 3x^2+a=0
a=-12
So 3x^2-12=0
x^2=4
x=2 or -2

if k is a constant and the max. value of y= k(x-4 )^2 +k^2 -k -2 is 4

when x=4, y has the maximum value
So k^2-k-2=4
k^2-k-6=0
(k-3)(k+2)=0
k=3 or -2
But since we have max. value of y, So k=-2

(6^x )^x =?

if y= log x then 1000^logx =?

y=logx
x=10^y

1000^logx
=1000^y
= (10^3)^y
=(10^y)^3
=x^3

2009-02-04 19:22:53 補充：
(6^x )^x cannot be simplified