If ∫g(x)dx=g(x), then ∫g(x){f(x)+f′(x)}dx is equal to
g(x)f(x)−g(x)f′(x)+C
g(x)f′(x)+C
g(x)f(x)+C
g(x)f2(x)+C
∫g(x){f(x)+f′(x)}dx =∫g(x)f(x)dx+∫g(x)f′(x)dx =f(x)(∫g(x)dx)−∫(f′(x)∫g(x)dx)dx+∫g(x)f′(x)dx =f(x)g(x)−∫g(x)f′(x)dx+∫g(x)f′(x)dx+C ( ∵∫g(x)dx=g(x)) =f(x)g(x)+C