3 tips for integraling:

Key 1:  ∫ sin(ax+b) dx = − 1/a cos(ax+b)+c     Such as  ∫ cos(3x+4) dx = 1/3 sin(3x+4) + c

Key 2:  ∫ 1/(ax+b) dx = 1/a ln|ax+b|+ c       Such as   ∫ 1/(3x+7)= 1/3 ln|3x+7|+ c

Key 3: When choose u and dv, For u, we should choose a simple one as u. we’d better think of du in order to integral dv easier.

Key 4: practice makes perfect