Alan/Val
Thanks, solving on my machine gives the right answers and no differance between answers. However, taking the 2c version you sent earlier and going with 10^-10 as suggested it does also give me the right answer. This is kind of weird and it would be good to be able to defend it. The question remains that the person using your spreadsheet might not have CTOL and TOL set to that level and will still get an answer, but a completely wrong answer. This creates a huge risk which those that want to resist the move to Mathcad will gladly exploit. Would be great if we could find a solution.