Compute the partial derivative of at, 3;) : m4 -l 69 with respect to 'r' where: :1:(r', s) : scos(2r') and y('r, s) : 45 l "r Your answer should have only the variables "r and s in it. 3f Answer. a =l l Answer entry help: Be careful with brackets, check how the system interprets your answer. Write v'u for I)" Write *u for I) - 'u, (* is required) Write *(u+w) for v('u, + 'w) (parenthesis and * are required) Write e"(u+v) for e (parenthesis are required) Write cos(theta) for COS i9 (parenthesis are required) Check