# how to do a Backward integration using ode_solver?

Let's say that i want to integrate this from ti=0 to tf=10

```
T=ode_solver()
f = lambda t,y:[y[1],y[0]^2-y[1]]
T.function=f
T.y_0=[0,.1]
T.t_span=[0,10]
T.ode_solve(num_points=100)
H= [ [T.solution[i][0] , T.solution[i][1][0] ,T.solution[i][1][1] ] for i in range(len(T.solution)) ]
for i in range(5): H[i]
[0, 0, 0.100000000000000]
[0.10000000000000001, 0.0095163351611087642, 0.090486759458914337]
[0.20000000000000001, 0.018128063040304006, 0.081894953217975602]
[0.30000000000000004, 0.025923510483407335, 0.0741488103498774]
[0.40000000000000002, 0.032983605743555654, 0.06717622415610694]
```

How i do to integrate backwards, from ti=10 to tf=0? This doesn't works, because the solution that it gives me is a constant = ti:

```
T=ode_solver()
f = lambda t,y:[y[1],y[0]^2-y[1]]
T.function=f
T.y_0=[10,.05]
T.t_span=[10,0]
T.ode_solve(num_points=100)
H= [ [T.solution[i][0] , T.solution[i][1][0] ,T.solution[i][1][1] ] for i in range(len(T.solution)) ]
for i in range(5): H[i]
[10, 10, 0.0500000000000000]
[10.0, 10.0, 0.050000000000000003]
[9.9000000000000004, 10.0, 0.050000000000000003]
[9.8000000000000007, 10.0, 0.050000000000000003]
[9.7000000000000011, 10.0, 0.050000000000000003]
```

Any advice using ode_solver()?