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chelslynn09
Aug 10, 2009, 01:23 PM
I just graduated High school and have used the quadratic formula numerous amounts of time... I haven't ever used the india method however and that is what I am being asked to do now... :mad:

How do I use the India method to solve the quadratic equations

a) x2 – 2x – 13 = 0
b) 4x2 – 4x + 3 = 0
c) X2 + 12 x – 64 = 0
d) 2x2 – 3x – 5 = 0

I would apreciate even the slightest amount of help!

*Thanks!

Unknown008
Aug 11, 2009, 09:18 AM
I don't understand neither... If you can solve a quadratic, then do! Why ask you to do it according to some method.

Here's a quote from my math teacher:


There are many methods to kill the cat, provided the cat is killed

Also, if you don't know that method, why didn't you ask the person who's asking you to solve by the 'India method', how to do it according to that method. There's no 'silly' questions if you don't know something. Also, the sooner the better, for it can get worse later on.

galactus
Aug 11, 2009, 12:39 PM
I haven't seen this method in a while. It is actually very old.

It's a nice way to solve quadratics. Perhaps it should be taught more.

It is just a variation on a theme, though.

#1: x^{2}-2x-13

Multiply everything by 4:

4x^{2}-8x=52

Add the square of the original x term to both sides:

4x^{2}-8x+4=56

Factor:

4(x-1)^{2}=56

Square root of both sides:

\pm 2(x-1)=2\sqrt{14}

x=\sqrt{14}+1, \;\ x=1-\sqrt{14}

That's it.