To find th vertex use the formula -b/2(a) so it's -8/2(1) so it's -4. Plug in the -4 into the original equation -4^2+8(-4)+3
16-32+3
-13
The vertex is (-4,-13)
It's minimum because the first coefficient is positive which means the parabola open up like a giant U and when plotted the vertex is a negative.