Answer:
B. a(t) = -3π²cos(πt)
Step-by-step explanation:
Acceleration is the second derivative of the position. Here, the second derivative of the cosine function is ...
d²(cos(πt))/dt²= -π²cos(πt)
Of course, the second derivative of the constant is zero. When we consider the multiplier of 3, we have ...
a(t) = x''(t) = -3π²cos(πt) . . . . . . . matches choice B
