八度程序解决ODE

Question

I have an ODE

dy=x dx,  y(0)=2

The solution of this equation is y =x^2/2 + K.

K become 2.

Now I have to plot graph. When

 x=0, y=2
 x=1, y=2.5
 x=2, y=4
 x=3, y=6.5
 x=4, y=10

I have to write an Octave program to generate these values

My code is test.m

function xdot = f (x,t)
 xdot=x;
 endfunction
 x=lsode("f",2,(t=linspace(0,4,5)));
 #plot(t,x)
 x

I run the pgm in cmd but it gives

2.0000
5.4366
14.7781
40.1711
109.1963

The expected result is

2
2.5
4
6.5
10

Please help me..

Answer 1

Finally got the answer..

Use

xdot=t;

instead of

xdot=x;