## anonymous 3 years ago Roots of quadratic:

1. anonymous

if α and β are the roots of equation 4x^2 - 2x - 1 = 0, find α - β

use formula : α - β = | (sqrt(D)/a) | with D=b^2-4ac

3. anonymous

oh yeah... forgot to put - without finding the roots So like using αβ = c/a and α+β=-b/a

right, but ur problem to find value of α - β?

5. anonymous

yes. find α - β

we know that general form of a quadratic equation is ax^2+bx+c=0 so, we can find α - β with formula : α - β = abs(sqrt(D)/a)

7. ParthKohli

You can always count on finding the roots and assuming them as $$\alpha, \beta$$.

8. ParthKohli

$x = {2 \pm \sqrt{4 - 4(4)(-1)} \over 8}$

9. anonymous

@ParthKohli, without finding roots

yea, right to.. but should use absolut sign because not known α > β or α < β

11. anonymous

yeah ok

13. anonymous

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