something like:
= 4*(A1)^3+6*(A1)^2+3*(A1)
?
Where A1 is the cell you enter the info
Dunno if it gives the right answer or not, but play with parentheses and you should get there eventually
edit
oh no, i think I got it backwards. I'm using x to get y, not the other way around.
something like this won't work?
http://www.wolframalpha.com/widgets/...30c90693eafc55
If you can write out your formula in terms of Y, then you should be able to get an equation to do this. i'm way to too tired to try to figure that out though