if such a thing wer none everyone becomes Mr.Perfect..........theres one basic technique so tat u feel them in ur bones bole to better understanding initial stages draw grafs 4 evry prob u do...nd get from nybook geometrical intepritation of addition subtraction multiplication division etc.....this technique is awsum only 4 freshers coz...once u no something abt it u feel it is ridiulous 2 draw grafs 4 silly things......so go 4 it..all the best....nd now..plz..rate me..