A.
[tex] f(t) = t^2 + 4t-14\\
f(t)=t^2+4t+4-18\\
f(t)=(t+2)^2-18
[/tex]
B.
[tex] f(x)=(x-h)^2+k \Rightarrow \text{vertex}=(h,k)\\\\
f(t)=(t+2)^2-18 \Rightarrow \text{vertex}=(-2,-18) [/tex]
It's a minimum, becuase [tex] a=1>0 [/tex].
C.
The axis of symmetry is [tex] x=h [/tex]. So, in this case, it's [tex] x=-2 [/tex].