Anyone with a graphing calculator?

Don't have the answer but i can give some advice there very cheap graphing calculator in store such as target I personally bought a Casio graphing calculator that we bought for about 40-60 bucks they usually go on sale around late July early to mid August during the time school start back up you can also find graphing calculator apps for the ipod touch or iphone and there are free online graphing calculator search it on google or yahoo or bing keywords would be free online graphing calculator