Find the general solution to y′′+4y=0y'' + 4y = 0y′′+4y=0.
y=C1cos(2x)+C2sin(2x)y = C_1 \cos(2x) + C_2 \sin(2x)y=C1cos(2x)+C2sin(2x)
y=C1e2x+C2e−2xy = C_1 e^{2x} + C_2 e^{-2x}y=C1e2x+C2e−2x
y=C1cos(4x)+C2sin(4x)y = C_1 \cos(4x) + C_2 \sin(4x)y=C1cos(4x)+C2sin(4x)
y=(C1+C2x)e2xy = (C_1 + C_2 x)e^{2x}y=(C1+C2x)e2x