Integration by Parts vs. U-Substitution

• U-substitution can be done whenever you have something containing a function (we’ll call this 𝑔), and that something is multiplied by the derivative of 𝑔
  • that is if you have ∫𝑓(𝑔(𝑥))𝑔′(𝑥)𝑑𝑥, use a u-sub
• Integration by parts is whenever you have two functions multiplied together—one that you can integrate, one that you can differentiate