Question

if alpha, beta are the roots of x^2 +kx+2=0.and alpha-beta=1,then k is

Answer 1

Hope this will help you.

Answer 2

Answer:

+or - 3

Step-by-step explanation:

$\alpha \beta$=2

$\alpha +\beta$= -k

$\alpha$-$\beta$= 1

$=(\alpha-\beta)^2= \alpha^2+ \beta^2-2\alpha\beta= (\alpha+\beta)^2-4\alpha\beta\\ \alpha+\beta = -k\\\substituting\\k^2-4(2)=1\\k^2-8=1\\k^2=1+8\\k^2=9\\k= \sqrt{9}$

k= + or - 3