Answer:
I imagine you aren't using calculus, so:
A: the leading term is [tex]1>0[/tex], so it opens upwards.
B. First coordinate of the vertex is [tex]-\frac b{2a}=-\frac42=-2[/tex], the second coordinate we'll find by replacing the value: [tex]f(-2)=(-2)^2+4(-2)-12 = 4-8-12=-16[/tex]
C. Quadratic formula or if you stare at the equation long enough you can rewrite the equation as [tex]f(x) = (x+6)\times(x-2)[/tex]. At this point the x intercepts are the zeroes of the function, or -6 and 2.
D. The y-intercept is the value of the function at 0, or the constant term: -12
E. The graph has a minimum since the curve opens upwards.