Answer
$b^{2}-4ac=-47$
Work Step by Step
$a=4,b=-1,c=3$
$ b^{2}-4ac\qquad$ ...substitute $4$ for $a,\ -1$ for $b$ and $3$ for $c$.
$=(-1)^{2}-4\cdot 4\cdot 3\qquad$ ...evaluate $(-1)^{2}$
$=1-4\cdot 4\cdot 3\qquad$ ...multiply before subtracting
$=1-48$
$=-47$
