helppp meeee!!!!!!! lsim

hi, I dont this problem with lsim, help me

di1/dt = -15000*i1 -10000*i2 +4000*i3 +5000*t^2+ 10000

di2/dt = -7000*i2 -3333,33*i1 -2666,66*i3+666,66*exp(t)+1666,66

di3/dt= -8500*i3 -4000*i2+ 2000*i1+25000

x0=[5.6,-4.82,6.51]

t=0:0.01:5;

my codes;

a=[-15000 -10000 4000; -3333.33 -7000 -2666.66; 2000 -4000 -8500];

b=[1 0 0;0 1 0;0 0 1];

c=[1 0 0;0 1 0;0 0 1];

d=[0 0 0;0 0 0;0 0 0];

x0=[5.6 -4.82 6.51];

t=0:0.01:5;

u=[(5000*(t.^2))+10000;(666.66*exp(t))+1666.66;25000];

[y x]=lsim(a,b,c,d,u,t,x0)

subplot(211),plot(t,x(:,1)),xlabel('t'),ylabel('vc')

grid,subplot(212),plot(t,x(:,2)),xlabel('t'),ylabel('il'),grid

ı think cause of error is matrix sizes are not equal or y function is not true

[Walter Roberson]

t=0:0.01:5;

t is a vector

 u=[(5000*(t.^2))+10000;(666.66*exp(t))+1666.66;25000];

The first row involves t so it is a vector the same length as t.

The second row involves t and is the same length as the first, which is good.. The third row is 25000 which is a scalar not the same length as t. You need to make copies of the 25000

But see also the description of u https://www.mathworks.com/help/control/ref/lsim.html

You are creating 3 rows but u would want 3 columns.