I'm doing a regression project inn Excel for my statistics class. One of the questions I'm supposed to solve for doesn't make any sense to me. I was hoping that someone could help clarify what exactly I'm supposed to do in this situation.

"Run a regression of the variable on a polynomial function on time and analyze the relationship. Fit the best model and decide on the degree of the polynomial."

I know how to run a regression of my variable on time but I don't understand where the polynomial function is supposed to come from or how I'm supposed to implement it into the regression. I don't think the polynomial function is my estimate y function from computing the regression of just my variable on time because I tried adding that to my regression in Excel and its t value was 0 so it's useless.