Conditional Formatting with results from formula

Question

In cell C1 I have a simple formula showing a net change from two other cells. =B1-A1

I would like to use the icon set in conditional formatting to show graphically the change, along with the result.

How do I define the conditional formatting to show only positive or negative results?

I would like the green arrow for positive changes and the red arrow for negative. I can get part of this to work, but if I change the data in A1 or B1, the conditional formatting doesn't change the result.

Answer 1

I suggest two rules, one merely to take precedence over the icon set when C1 is zero (as adjusted for the accuracy required):

In the image the value in B1 is 99.99999