Hi, I am trying to write a short matlab program that plots concentration vs distance (oxygen sag curve from two different bod sources in a river). I know the equation im using is: C= Cs - [(kd*Mo)*(exp(-x*kr/u)-exp(-x*ka/u))/(Q*ka-kr)] - (Cs-Co)*exp(-x*ka/u) - [(kd*Mo)*(exp(-(x-L)*kr/u)-exp(-(x-L)*ka/u))/(Q*ka-kr)]. Its very long and im having trouble getting it to work in matlab form. Can someone used to matlab give me some hints how to make this work? I know how to execute a plot by plot(x,C) but the equation is giving me trouble. Any help would be greatly appreciated. Thanks.