Question :

Give that α & β are roots of the equation 2x^{2 }+ 5x - 7 = 0

Find without solving the equation the value of (α -β)^{2}

Need to calculate the sum of the root and the product of the roots

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- Nov 18th 2012, 11:39 AML44Need help with roots of a equation
Question :

Give that α & β are roots of the equation 2x^{2 }+ 5x - 7 = 0

Find without solving the equation the value of (α -β)^{2}

Need to calculate the sum of the root and the product of the roots - Nov 18th 2012, 11:49 AMPlatoRe: Need help with roots of a equation
- Nov 18th 2012, 11:55 AML44Re: Need help with roots of a equation
Yes I know that part. need to find the equation for the (α -β)2

roots - Nov 18th 2012, 12:19 PMPlatoRe: Need help with roots of a equation
- Nov 18th 2012, 12:19 PMskeeterRe: Need help with roots of a equation
,

- Nov 18th 2012, 12:24 PML44Re: Need help with roots of a equation
I have that part the answer I got was 20 1/4 but is the working of the sum of the roots part (α -β)^2 where I have (α -β) + (α -β) unable to figure out the value

- Nov 18th 2012, 01:36 PMSorobanRe: Need help with roots of a equation
Hello, L44!

Quote:

Need to calculate the sum of the roots and the product of the roots

You said that you already know that: .

Square [1]: .

-4 times [2]: .

Add [3] and [4]: .

Therefore: .