Don't really know what to do with this one, any help welcome
If A, B and α are constants, independent of x, and
y= Acosαx + Bsinαx
Evaluate the derivates
y'=dy/dx
y^n=d^2y/dx^2
Determine values of A, B and α such that y satisfies
y^n+y=0 and y(0)=0, y'(0)=1
I've tried to differentiate y
y'=-αAsinαx + αBcosαx
y'=αBcosαx - αAsinαx
y^n=-ααBsinαx + ααAcosαx
y^n=ααAcosαx - ααBsinαx