Help pls decide this Differential Equations!I did not coincide with the answer and in some no idea how to do! will be very grateful if you start a proper solution to Us
1) y(4)+2*a2*y''+a4*y= cos(ax)
2) y' = x + 1/y; y(0)=1
3) y' = 2*x + cos(y); y(0) = 0
4) y(x) - λ*(0 to...