Mr joe thank you. If we have two time $20n^2$ and $n^2$ I know when we use the Big-O should be omitted coefficient. But practically when drawing functions note the existence of a difference between the two, can we say $n^2$ better than $20n^2$. Graphically

Mr Rick Decker thank you very much. now I understand.

But when I draw curve for two equation I note the first time take time greter than second time because coefficient large . Can say that.

Mr Rick Decker. Do you mean that two algorithms hava the same growth rate = $O{log n})^3$