(a) Evaluate the following indefinite integrals. Show complete working. In particular: if you use substitution, write down the substitution that you used. Show the full working needed to make that substitution. Write your final answer in terms of a. if you use partial fraction decomposition, show the complete working that is needed to find theappropriate partial fraction expression. if you use integration by parts, indicate which part of the integration and corresponds to corresponds to v in this formula?du/dx vdx= uv =-?u dv/dx dx(Note: the integrand is the function inside the integral that we want to integrate.)1. ?1/x²-1 dx2. ? e^x cos h(3ex)dx3. ? x ln xdx