(Solved): Only 3 and 5 please Apply the given operator to the given functions. Show all steps in detail. 1. \( ...

Apply the given operator to the given functions. Show all steps in detail. 1. \( D^{2}+2 D ; \quad \cosh 2 x, e^{-x}+e^{2 x}, \cos x \) 2. \( D-3 I ; 3 x^{2}+3 x, 3 e^{3 x}, \cos 4 x-\sin 4 x \) 3. \( (D-2 I)^{2} ; e^{2 x}, x e^{2 x}, e^{-2 x} \) 4. \( (D+6 I)^{2} ; \quad 6 x+\sin 6 x, x e^{-6 x} \) 5. \( (D-2 I)(D+3 I) ; \quad e^{2 x}, x e^{2 x}, e^{-3 x} \)