1 | initial version |

As to the first question, use `subs`

:

```
sage: def test(f,myvar,myval):
return f.subs(myvar==myval)
....:
sage: print(test(f,x,3))
9
```

In general, Sage comes with source, see https://github.com/sagemath/sage
Regarding the `plot`

question, the triple is a standard Python tuple. I would
need a more specific question to elaborate further.

2 | No.2 Revision |

As to the first question, use `subs`

:

```
sage: def test(f,myvar,myval):
return f.subs(myvar==myval)
....:
sage: f = x^2
sage: print(test(f,x,3))
9
```

In general, Sage comes with source, see https://github.com/sagemath/sage
Regarding the `plot`

question, the triple is a standard Python tuple. I would
need a more specific question to elaborate further.

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.