# Visual Limits for Programmers
Canonical public lesson for limits.
## One picture
A limit asks what value a function approaches as the input gets close to something.
```text
x gets close to a → f(x) gets close to L
```
## Simple idea
You do not always need to stand exactly on the point. You can watch where the values are heading.
## Programmer view
```python
for x in [1.9, 1.99, 1.999, 2.001, 2.01, 2.1]:
print(x, f(x))
```
If outputs squeeze toward the same value from both sides, that value is the limit.
## Why it matters
Limits make derivatives possible: zoom in until a curve behaves like a line.
Source task: `803924d4-bd9f-4fe3-b060-8f676601a837`