Question: What is the solution to the differential equation y\'\' + 4y = 0?
Options:
Correct Answer: y = C1 cos(2x) + C2 sin(2x)
Solution:
This is a second-order linear homogeneous differential equation. The characteristic equation has roots ±2i, leading to the solution y = C1 cos(2x) + C2 sin(2x).