### Problem with plotting "lambda" functions

The following code returns AttributeError

```
F(x, k) = gamma_inc_lower(k/2, x/2) / gamma(k/2)
plot((lambda k: find_root(F(x, k) - 1/2, 0, 100)), (k, 1, 10))
```

I think there is some problem with coercion of Python function to Sage function, but I have no idea how to solve it in an elegant way.

Any solution, please?