And so this is going to be equal to, this is equal to negative nine times, I'm gonna create some space here. So, actually that's probably more space than I need. It's going to be cosine of six pi. Cosine of six, six pi. Cosine of six pi minus, minus cosine of 11 pi over two. Cosine of 11 pi over two. Well what is cosine of six pi going to be?