Never mind, I got it
Having established that ,
I need to express in terms of pi by using the properties of intergrals (linearity with respect to the integrand, additivity with respect to the interval of integration, invariance under translation, and expansion/ contraction of the interval of integration).
I can get as far as , and according to the book, the answer is -6pi, so if I'm right so far, the first integral evaluates to 0. I just don't know how to show this.