Question 5: [30 marks] Determine which of the differentials (or both) is the total differential: a) 2[exp(2x + 2y-) + x] dx + [4yexp(2x + 2y-) + 1] dy; [15 marks] b) 6sin(y) ed*/dx + 3(siny + cosy)exy -2ysin(y ) dy. [15 marks] Find the potential function U(x, y) subject to the condition U(0, 0) = 5 in the case of the total differential. Rubric: 3 marks if the total differential was determined correctly in case (@); 6 marks if the potential function was derived correctly in case (@); 3