Final answer:
To find the general solution of the differential equation, assume the general form of the solution.
Step-by-step explanation:
To find the general solution of the given differential equation: y(4) + 8y'' + 16y = 0,
we can assume the general form of the solution in regions I and III to be:
y(x) = C1eλ1x + C2eλ2x + C3cos(αx) + C4sin(αx)
where λ1, λ2, α, C1, C2, C3, C4 are arbitrary constants to be determined.