Find the general solution to y′′+y=0y'' + y = 0y′′+y=0.
y=C1cosx+C2sinxy = C_1 \cos x + C_2 \sin xy=C1cosx+C2sinx
y=C1ex+C2e−xy = C_1 e^x + C_2 e^{-x}y=C1ex+C2e−x
y=Cexy = C e^xy=Cex
y=C1cos(x2)+C2sin(x2)y = C_1 \cos(x^2) + C_2 \sin(x^2)y=C1cos(x2)+C2sin(x2)