Answer:
α =

Step-by-step explanation:
The angle, θ, has been given as:
θ =

To obtain angular acceleration, α, we have to differentiate the angle twice, with respect to time, t.
Differentiating once will yield the angular velocity, ω:
ω = dθ/dt =

This can then be differentiated to obtain angular acceleration:
α = dω/dt =
