1.Let r1 and r2 be the two real roots of the equation (x-2006)(x-2007)=2007. if r is the smaller real root of the equation (x-r1)(x-r2)=-2007,find the value of r.
2.the area of the largest rectangle with perimeter 1 metre is b square metre,find the value of b.
3.x^y+x^-y=(2)2^(1/2) and x^y-x^-y=k,where x>1 and y>0,find the value of k.
4.48^x=2 48^y=3 if 8^((x+y)/(1-x-y))=b find the value of b.
5.suppose x^(1/2)+x^(-1/2)=3 and b=(x^(3/2)+x^(-3/2)-3)/(x^2+(x^-2)-2),find the value of b.
唔比用計數機help= =作者: -終場ソ使者- 時間: 13-12-2011 20:06
1)
What is b?
2)
just form a suitable equation to find the relevant length and width!
3)
Therefore, (*)
k=2 or -2 from (*)
for x>1 and y>0,
help= =
(*)
,
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, from (*)