The stability of periodic differantial equations

Differential equations with periodic coefficients are of considerable interest to both mathematicians and physicists. In this thesis, we studied the spectral analysis of periodic differential equations. Since the Floquet theory is very important for the periodic differential equations, first we introduced the Floquet theory and applied to our considered problem. By using this theory and analysing of the function , which is also called discriminant, we determined the stability and instability intervals of the problem.