Question

if a and b are the root of x²+6x-4=0.f ind the value of(a-b)²​

Answer 1

Given :

a and b are roots

x² + 6x - 4

$\implies \: a \: + b \: = \dfrac{ - 6}{1}$

Also,

$\implies \: \: a \times b \: = \dfrac{ - 4}{1}$

Now,

$\bull \: \: \: \: \: \: \: \: \: \boxed{ {(a - b)}^{2} = {a}^{2} + {b}^{2} - 2ab}$

$= - 6 \: ^{2} - 2( - 4) = 36 - 8 \\ = 28$