**Python math domain error using math.acos function** :

**SOLUTION 1 :**

You are trying to do `acos`

of a number for which the `acos`

does not exist.

```
Acos - Arccosine , which is the inverse of cosine function.
```

The value of input for acos range from `-1 <= x <= 1`

.

Hence , when trying to do – `math.acos(1.0000000000000002)`

you are getting the error.

If you try higher numbers, you will keep getting the same error – `math.acos(2)`

– leads to – `ValueError: math domain error`

**SOLUTION 2 : **

Inverse cosine is defined only between -1 and 1, inclusive. The arc-cosine of 1.0000000000000002 has no mathematical or semantic meaning other than “does not exist” or “undefined”.

Of course, since inverse cosine of 1 does exist, acos(1) doesn’t throw any error.