미분방정식 $y ''-2y '+y= (t^2 +2) e^t, y (0) =0, y ' (0) =0$ 의 해는?

• ①$\displaystyle y= \left (\frac{t^4} {12} +t^2 \right) e^t$
• ②$\displaystyle y= \left (\frac{t^4} {12} + 2t^2 \right) e^t$
• ③$\displaystyle y= \left (\frac{t^4} {12} +t^2 \right) e^ {-t}$
• ④$\displaystyle y= \left (\frac{t^4} {12} +2t^2 \right) e^ {-t}$