1. The problem statement, all variables and given/known data For a related rate problem I am only given the two rates say dx/dt=1 and dy/dt=2 and a the function which depends on both x and y say f(x,y)=4xy^2 find how it is changing at T=3 2. Relevant equations Chain rule 3. The attempt at a solution So I can take both partial derivatives with respect to the chain rule and sub in 1 and 2 for the dx/dt and dy/dt respectively I just have no idea how T comes into play and what to sub in for x and y. My thoughts are that possibly since dx/dt=1 and dy/dt=2 then y=2x and I can isolate for the one variable but then I still dont know what to do form there.