Algeb

• May 16th 2012, 10:15 PM
srirahulan
Algeb
$\mbox{if}\ a^2x^2+6abx+ac+8b^2=0\ \mbox{have equal roots then,prove}\ ac(x+1)^2 =4b^2x\ \mbox{have equal roots.}$
• May 16th 2012, 11:08 PM
Goku
Re: Algeb
use the quadratic formula for the first one and solve:

$\frac{-6ab \pm \sqrt{36a^2b^2 - 4a^2(ac+8b^2)}}{2a^2}$

find the 2 solution and equate......
• May 17th 2012, 04:48 AM
srirahulan
Re: Algeb
I can't understand.
• May 17th 2012, 05:00 AM
Goku
Re: Algeb
Suppose that $a^2x^2+6abx+ac+8b^2$ has equal roots,

what will this mean....

First Solve the equation using the quadratic equation and tell me what you get....
• May 17th 2012, 05:24 AM
Wilmer
Re: Algeb
Quote:

$\frac{-6ab \pm \sqrt{36a^2b^2 - 4a^2(ac+8b^2)}}{2a^2}$
For roots to be equal, discriminant = 0, right? So:
36 a^2 b^2 = 4 a^2(ac + 8 b^2); simplifies to b^2 = ac

Now continue with other equation...