Question

Use f(x) = x^2 + 4x - 12

Answer 1

Answer:

I imagine you aren't using calculus, so:

A: the leading term is $1>0$, so it opens upwards.

B. First coordinate of the vertex is $-\frac b{2a}=-\frac42=-2$, the second coordinate we'll find by replacing the value: $f(-2)=(-2)^2+4(-2)-12 = 4-8-12=-16$

C. Quadratic formula or if you stare at the equation long enough you can rewrite the equation as  $f(x) = (x+6)\times(x-2)$. 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.