Solving for a & b: Increasing GP Equations

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utkarshakash
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Homework Statement


If [itex]x_1,x_2[/itex] are the roots of [itex]x^2-3x+a=0[/itex] and [itex]x_3,x_4[/itex] are the roots of the equation [itex]x^2-12x+b=0[/itex] and [itex]x_1,x_2,x_3,x_4[/itex] are in increasing G.P., find a and b

Homework Equations



The Attempt at a Solution


[itex]x_1+x_2=3 \\<br /> x_1x_2=a \\<br /> x_3+x_4=12 \\<br /> x_3x_4=b[/itex]

But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?
 
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utkarshakash said:

Homework Statement


If [itex]x_1,x_2[/itex] are the roots of [itex]x^2-3x+a=0[/itex] and [itex]x_3,x_4[/itex] are the roots of the equation [itex]x^2-12x+b=0[/itex] and [itex]x_1,x_2,x_3,x_4[/itex] are in increasing G.P., find a and b

Homework Equations



The Attempt at a Solution


[itex]x_1+x_2=3 \\<br /> x_1x_2=a \\<br /> x_3+x_4=12 \\<br /> x_3x_4=b[/itex]

But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?
G.P. = Geometric Progression

http://en.wikipedia.org/wiki/Geometric_progression
 
utkarshakash said:
But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?

It means that the common ratio of the GP is greater than 1.
 
Pranav-Arora said:
It means that the common ratio of the GP is greater than 1.

This means that [itex]x_1<x_2<x_3<x_4[/itex]
But what is the use of this in my question?
 
utkarshakash said:
This means that [itex]x_1<x_2<x_3<x_4[/itex]
But what is the use of this in my question?

Ignoring that detail for the moment, simply try answer the question and then you'll see.