Answer
$\Delta_f<0$
$\Delta_g>0$
$\Delta_h=0$
$\Delta_j=0$
Work Step by Step
Let $\Delta$ be the discriminant.
The graph of $f$ does not intersect the $x$-axis, so its discriminant is negative:
$$\Delta_f<0$$
The graph of $g$ intersects the $x$-axis two times, so itsdiscriminant is positive:
$$\Delta_g>0$$
The graph of $h$ intersects the $x$-axis once, so its discriminant is zero:
$$\Delta_h=0$$
The graph of $j$ intersects the $x$-axis once, so its discriminant is zero:
$$\Delta_j<0$$
