u^{''}=\H(t)

解答

u^{^{''}} = H (t)

u (t) = \int \int H (t) d t d t

求解步骤

u^{''} (t) = H (t)

解

u^{''} (t) = H (t) : u^{'} (t) = \int H (t) d t

解

u^{'} (t) = \int H (t) d t : u (t) = \int \int H (t) d t d t

u (t) = \int \int H (t) d t d t

0.25 \cdot 0.04 x^{^{''}} + 2 \cdot 0.04 x^{^{'}} + x = 0

y^{^{''}} + 20 y^{^{'}} + 92 y = 0

33 y^{^{''''}} + 23 y^{^{''}} + 4 y = 0

y^{^{''''}} - 5 y^{^{'''}} + 6 y^{^{''}} + 4 y^{^{'}} - 8 y = 0

y^{^{''}} - 10 y^{^{'}} + 25 y = 0, y (0) = - 3, y^{^{'}} (0) = - \frac{68}{5}