i figured it out, the #num was screwing up for the test if a2=0, i had to do
=if(iserror(a1),b0,if(a1=0,b0,1/a1-1/2.5))

"Toppers" wrote:

How is "bo" defined? Using it, I get a #NAME! error.

"bastien86" wrote:

The formula works fine for

=if(iserror(a1),b0,1/a1-1/2.5)

but then i have 0 in my a column and it screws up the false part cause 1/0
gives div/0

i want to say iserror or a1=0 but i get problems:\