Step 1 We begin with the left side. Remembering that y is a function of x, we have [4 sin(x) + cos(y)] - 4 cos(x) dx 4 cos(x) sin() sin(y) Step 2 Now on the right side, note that sin(x) cos(y) is a product, and so we must apply the Product Rule. We, therefore, have (sin(x) cos(y)] = sin(x)( sin(y) + cos(Y)(cos(x)) dx X Tutorial Exercise Find dy/dx by implicit differentiation. 4 sin(x) + cos(y) = sin(x) cos(y)