Answer:
A)  The vertex ( h , k) = ( -2 , -18)
B) The minimum value of the given function = - 18
C) The Axis of the symmetry for f(t) is y -axis
Step-by-step explanation:
A) 
Given a parabola   f(t) = t² + 4 t − 14
                                f(t) =  t² + 2(2) t + (2)²-4− 14
                            f(t) = (t +2)² - 18
Let comparing  y = (x +2)² -18
                    (x +2)² = y + 18
                    (x-h))² = 4 a ( y - k))²
<em>The vertex ( h , k) = ( -2 , -18)</em>
B) 
   Given a parabola   f(t) = t² + 4 t − 14
   Differentiating with respective to 't'
                                  f¹(t) = 2 t + 4
                                   f¹(t) = 2 t + 4 = 0
 now                      
Again Differentiating with respective to 't'
                     
f(x) has a minimum value at t = -2
Given f(t) = t² + 4 t − 14
          f( -2) = 4 + 4(-2) -14 = 4 -8 -14 = -18
The minimum value of the given function = - 18
C) 
  f(t) = (t +2)² - 18
Let comparing  y = (x +2)² -18
                    (x +2)² = y + 18
                    (x-h))² = 4 a ( y - k))²
The vertex ( h , k) = ( -2 , -18)
The Axis of the symmetry for f(t) is y -axis