When can Java produce a NaN?

Question

I know what Java Double.NaN is. I have some Java code that produces NaN.

// calculate errors
delta = m1 + m2 - M;
eta = f1 + f2          


        

Answer 1

NaN is triggered by the following occurrences:

• results that are complex values
  • √x where x is negative
  • log(x) where x is negative
  • tan(x) where x mod 180 is 90
  • asin(x) or acos(x) where x is outside [-1..1]
• 0/0
• ∞/∞
• ∞/−∞
• −∞/∞
• −∞/−∞
• 0×∞
• 0×−∞
• 1^∞
• ∞ + (−∞)
• (−∞) + ∞

Sorry for such a general answer, but I hope that helped.