The problem is that `x`

is a symbolic expression, and it does not have a `eint`

method. So, instead of plotting a smybolic expression, you should try to plot a Python function:

```
sage: def eint(x):
....: return RR(x).eint()
```

Now, you can plot this function:

```
sage: plot(eint, [-1,1], frame=True)
```

Note that i had to transform `x`

as an element of `RR`

, because the `plot`

function iterates over some elements of `[-1,1]`

viewed as Pyhon `floats`

which do not have a `eint`

method either:

```
sage: float(1.1).eint()
AttributeError: 'float' object has no attribute 'eint'
```

You can see what happens if we omit to convert the float elements into `RR`

:

```
sage: def eint_noconvert(x):
....: return x.eint()
sage: plot(eint_noconvert, [-1,1], frame=True)
AttributeError: 'float' object has no attribute 'eint'
```