Simple question



I've been messing about with maxima for a little bit now and have to 
say that i'm very impressed.  It's a great way for a beginning math 
student to explore some of concepts encountered.  Thanks for all the 
hard work.

Question: how would I put in the quadratic function?  I can get 
everything in except the -+

Thanks,
Justin KL1RL
Fairbanks AK