Attempt the question, check the explanation, and continue with similar questions to build confidence before exams.
∫udv = uv - ∫vdu
∫uv = u∫dv + v∫du
uv = ∫udv + ∫vdu
∫udv = ∫du + ∫vdv
Continue with nearby questions to strengthen the same chapter concept while you still have the context fresh in mind.