Standard +0.8 This is a standard Further Maths second-order differential equation requiring both complementary function (repeated root case with auxiliary equation m²+4m+4=0) and particular integral (polynomial trial solution). While methodical, it involves multiple techniques and algebraic manipulation beyond standard A-level, placing it moderately above average difficulty.
2 Find the general solution of the differential equation
$$\frac { \mathrm { d } ^ { 2 } x } { \mathrm {~d} t ^ { 2 } } + 4 \frac { \mathrm {~d} x } { \mathrm {~d} t } + 4 x = 7 - 2 t ^ { 2 }$$