Question

if alpha and beta are the roots of the equation 2x^2+5x-4=0 find the value of alpha^2+beta^2​

Answer 1

let alpha be =a

and beta be = b

$2 {x }^{2} + 5x - 4$

a+b =-b/a = -5/2

ab=c/a =-4/2=-2

then

a2+b2 =(a+b)2 -2ab

=(-5/2)2 - (-2)

=25/4+ 4

=25