This is going to be equal to the definite integral from negative one to zero of f of x dx plus the integral from zero to one of f of x dx. Now, why was it useful for me to split it up this way? And in particular, to split it up, split the interval from negative one to one, split it into two intervals from negative one to zero and zero to one? Well, I did that because zero, x equals zero is where we switch, where f of x switches from being x plus one to cosine pi x. So if you look at the interval from negative one to zero, f of x is x plus one. So f of x here is x plus one. And then when you go from zero to one, f of x is cosine pi x.