Let's perform the differentiation: (x·sin(x))' For U1 = x and V2 = sin(x), use the product/quotient rule: (U1·V2)' = (U1)'·V2 + U1·(V2)' Let's differentiate U1: (x)' 1 Let's perform the differentiation V2: (sin(x))' cos(x) You can evaluate the resulted derivative (U1·V2)': 1·sin(x) + x·cos(x) sin(x) + x·cos(x) ▷Answer: x·cos(x) + sin(x)