## list of tricks

**: If the function we are trying to integrate is “x” times “something”, (e.g. xsin(x)), it is usually a good idea to let x=g(x), and the rest to be f’(x). This is because the derivative of x is 1. The problem is reduced to finding the integral of that “something”.**

__Trick #1____: If there is an e^x in the equation, it can serve both as an f’(x) or g(x). This is because both the integral and the derivative of e^x is itself. We can decide if we want to have the derivative of the rest of the function or its integral. Usually, we want its derivative, as it is often much easier to find.__

**Trick #2****: If there is a square root in the equation, integration by parts would often not work.**

__Trick #3 (not technically a trick)____: Sometimes, we can apply integration by parts many, many times. Remember that we have transformed the function to be integrated into another one? We can transform it again, and again. Until we find the result. But take a note—if you can’t find the answer in three tries of integration by parts, you’d better try the other way.__

**Trick #4**