（1）先计算右边式子的值；
% Step 1
syms t; u=exp(-5*t)*cos(2*t+1)+5;
uu=5*diff(u,t,2)+4*diff(u,t)+2*u
打印
uu =
87*exp(-5*t)*cos(2*t + 1) + 92*exp(-5*t)*sin(2*t + 1) + 10
（2）在计算左边式子的值；好像新版的matlab dsolve函数格式发生了一点点改变，使用dsolve函数时先help dsolve一下。
% Step 2
syms y(t)
eqn = diff(y,t,4)+10*diff(y,t,3)+35*diff(y,t,2)+50*diff(y,t)+24*y == 87*exp(-5*t)*cos(2*t+1)+92*exp(-5*t)*sin(2*t+1)+10
y=dsolve(eqn)
打印
y =
(exp(-5*t)*(445*cos(2*t + 1) - 65*exp(5*t) + 102*sin(2*t + 1)))/26 - (exp(-5*t)*(537*cos(2*t + 1) - 40*exp(5*t) + 15*sin(2*t + 1)))/24 - (exp(-5*t)*(25*exp(5*t) - 542*cos(2*t + 1) + 164*sin(2*t + 1)))/60 - exp(-t)*((133*exp(-4*t)*cos(2*t + 1))/30 - (5*exp(t))/3 + (97*exp(-4*t)*sin(2*t + 1))/60) + C1*exp(-4*t) + C2*exp(-3*t) + C3*exp(-2*t) + C4*exp(-t)
