Question

If $a,b\in \{1,2,3\}$ and the equation $a{x}^2+bx+1=0$ has real roots, then

Answer 1

$a{x}^2+bx+1=0$
For real roots, $D\ge 0$
$b^2-4a\ge 0\Rightarrow b^2\ge 4a$
Possible pairs of $(a,b)$ are $(1,2),(1,3),(2,3)$