The correct answer is: \(I=\frac{e^x}{x}+C\) Let \(I=∫e^x[\frac{1}{x}-\frac{1}{x^2}]dx\) Also,let \(\frac{1}{x}=ƒ(x)\,ƒ'(x)=\frac{-1}{x^2}\) It is known that,\(∫e^x[ƒ(x)+ƒ'(x)]dx=e^x ƒ(x)+C\) \(∴I=\frac{e^x}{x}+C\)
The number of formulas used to decompose the given improper rational functions is given below. By using the given expressions, we can quickly write the integrand as a sum of proper rational functions.