Bend Calculation Tables?

I'm trying to make a bend deduction formula in the "bend calculations". I modified the bend_calculation.xls and noticed a few things:

-it understands "tan(b)" but not "sin(b)" or "cos(b)"

--I tried to substitue and only use tan(b) in my equation but solidworks once again has trouble reading it since I now have instances of tan(b)^2 or tan(b)*tan(b)

-if i make the equation as "v=0" and put "tangency" on it basically adds 2*(r+s) to the bend allowance automatically

is there any documentation on how to apply formulas such as sin(b), k^2, etc? The help files don't seem to fill me in on how tangency/no tangency is calculated. Has anyone else successfuly made a formula with this "Bend Calculation" method?

It seems to me like this feature is not fully developed

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