Respuesta :

Answer:

a = 132 m/s^2

Explanation:

f(t) = t^4 − 2t^3 − 6t^2 + 9t

v = f'(t) = 4t^3 - 6t^2 - 12t + 9

a = f''(t) = 12t^2 - 12t -12

Substitute t = 4 seconds into the equation for a:

a = 12(16) -12(4) -12 = 132 m/s^2