Hi Colin, Checking that values are in range in order to call a built in function, procedure etc is normal. At least it as been for as long as I've been programming - since pre ZX81 days.
Even now I still check and this includes when writing code to run on my numerous Oracle databases - which today calculated VV to be 1 for the values given, with A corrected and parenthesis around the A^2, B^2 and C^2 part. It was well off without the parenthesis, but I can't remember the actual value. (15e-10 possibly, but don't quote me!) Defensive Programming is what it used to be called, but in these days of "agile" (hack, spit) so - called programming, it's probably not done any more! Og course, one could imagine that ACOS itself would practice such things, and it appears that it does, giving you an error when the parameter goes out of range. HTH Cheers, Norm. -- Sent from my Android device with K-9 Mail. Please excuse my brevity. _______________________________________________ QL-Users Mailing List
