SQL SERVER ‐ POWER issue - FalconFT/FalconDocs GitHub Wiki
--(-8)^(1/3) --> an integer, -2 --(-8)^(0.33333333333333) --> a complex number
That is, floating point values are inexact and cannot represent something like one-third. And the value has to be exactly 1/3 in order for the value to be a floating point number.
Let suppose you have to calculate 5√(-15.0) (fifth root of -15), which is the same as POWER(-15.0, 0.2). The correct result of this expression is -1.730080613. But if you try to run
SELECT POWER (-15.0, 0.2)
you will get “An invalid floating point operation occurred.” error.
You’ll get the same error in all cases where the base is a negative number and exponent is not an integer.