# Basic Trig Integral Question.

by NewtonianAlch
Tags: basic, integral, trig
 P: 440 1. The problem statement, all variables and given/known data This question is part of Fourier Series in Circuit Analysis. There were fairly straightforward integrals which I calculated and confirmed using MAPLE to be correct, however the book gives somewhat different answers. I would presume that what I did was correct and the solutions manual made an error, however since it's a fairly large question with answers being carried forward I want to make doubly sure. Sorry about the size of the images, I will remove them after the problem This is the integral essentially, the definite integral from 2 to 4 is left out because it's zero, f(t) = 5 for 0 < t < 1 f(t) = 10 for 1 < t < 2 2. Relevant equations cos (Pi/2) = (-1)$^{\frac{n-1}{2}}$ cos (Pi) = (-1)$^{n}$ 3. The attempt at a solution My answer came to this: EDIT: cos(nPi/2) goes to (-1)^n/2 - still doesn't reconcile my answers with the book though. The MAPLE output was: $5\,{\frac {1+\cos \left( 1/2\,n\pi \right) -2\,\cos \left( n\pi \right) }{n\pi }}$ The answer in the book was (last line before the table): As you can imagine, because the answers are different, the values in the table are going to be different and hence whatever I have to plot afterwards will be different.