Compute the partial derivative of f(x, y) - at + ev with respect to r where: RT, S - S COS(47) and y(T, 8 - 53 + T Your answer should have only the variables r and s in it. of Answer: ar Answer entry help: Be careful with brackets, check how the system interprets your answer. Write v^u for vu Write v*u for v . u (* is required) Write v*(u+w) for v(u + w) (parenthesis and * are required) Write e^(utv) for e (parenthesis are required) Write cos(theta) for cos 0 (parenthesis are required)