And so then we would want to test it. And we could set up a traditional table that you might have seen before where we have our interval or intervals. We could have test values in our intervals. We have to be careful with those, make sure that they are indicative. And then we would say the sine of our second derivative of g prime prime. And then we would have our concavity, concavity of g. And in order for x equals zero to be an inflection point, we would have to switch sines as, or our second derivative would have to switch sines as we cross x equals zero, and which would mean our concavity of g switches sines as we go, as we cross x equals zero. So let's do values less than zero, negative infinity to zero, and then values greater than zero, infinity, zero to infinity.