# In Go, NaN does not equal NaN

It’s false, it returns false.

`fmt.Println(math.NaN == math.NaN)`

Don’t fret though, there is a function that can tell you whether or not a value is `NaN`

.

`fmt.Println(math.IsNaN(math.Log(-1.0)))`

The above returns true and all is well with the world. Don’t use math.NaN as a sentinel value, it does not work, use the `math.IsNaN`

function.