Hello,

here's how I would have done :

I would have created a column named in A1. In A2, I put "=-20". Then, in A3, I put "=A2 + 1". Then I use the quick formula copy, so that I get a column of . Then, in B1, I put , and in B2 I write "=6*A2*A2 + 3*A2 -18. Then I use the quick formula copy to extend the column as far as the column goes. Thus I get two sets of data, and , which I can plot using the graph wizard