# please explain math.sqrt(n)

Hello Dear all

I tried understand :

```
import math
n=115792089237316195423570985008687907852837564279074904382605163141518161494337
d= math.sqrt(n)
print(d)
print(d==2**128)
print(d*d==n)
u=d*d
print(u)
print(n-u)
```

result: how it is possibility that sqrt(n) *sqrt(n) is equal n if it is not?:)