Copy the above function code (the first four code lines) into the Function box and change it so it takes two functions f and g and one number a and so it finds the derivative of the composition , plugs in (read that carefully!) and returns that value. Then submit it. This was the above function code: function r = myderivatpoint(f,a) syms x r = subs(diff(f(x)),x,a); end I also don't know how I'd call the code to function in this. Thanks..