im doing my traffic analysis homework and i dont understand how they went from "1" to "2" in the picture below. more specifically i dont know if im taking the derivative wrong or if they are (those who wrote the solution). if you distribute the "k" thats at the beginning of the equation, you will get: q = uf (k - [(k2))/kj]3.5)=0 then if i distribute the 3.5 power, i should get: q = uf (k-[(k5.5)/(kj3.5)] = 0 then if i take dq/dk of this, shouldnt i get: dq/dk= uf(1-[(5.5k4.5)/(kj3.5)] ???? the pic below is a screenshot of the solution, and theyre getting dq/dk to be: dq/dk= uf(1-[(4.5k3.5)/(kj3.5)] are they wrong?