1 | initial version |

Your construction does not really makes sense : (f+pt1).show(xmin= xmin, xmax= xmax, ymin=-20, ymax=20) does not return anything, since the `show`

method does just plot something, but does not return any object, hence the construction of `z`

corresponds to the empty graph, and you can check:

```
sage: z == Graph(None)
True
```

So, what do you want to achieve ?

2 | No.2 Revision |

Your construction does not really makes sense : (f+pt1).show(xmin= xmin, xmax= xmax, ymin=-20, ymax=20) does not return anything, since the `show`

method does just plot something, but does not return any object, hence the construction of `z`

corresponds to the empty graph, and you can check:

```
sage: z == Graph(None)
True
```

So, what do you want to achieve ?

**EDIT**

Only the following 4 lines are useful:

```
xmin = -10
xmax = 10
f = plot((x^2-2)/(x+2), (x,xmin, xmax), ymin = -20, ymax = 20)
pt1 = point((-2,2), rgbcolor='blue', pointsize=40)
```

Everything else is about discrete graphs (those with vertices and edges), not with functionnal graphs, nor graphics.

It turns out that `matplotlib`

, which Sage uses to render such plots is able to export to latex (using `pgf`

package), and Sage has a an interface to it. You can do:

```
latex(f+pt1)
```

and copy-paste the long text you get into your latex file. To let the code work, you have to add the `pgf`

package in your latex file:

```
\usepackage{pgf}
```

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