. Let $\delta>0$ be given. Consider an interest rate swap paying a fixed interest rate $K$ and receiving backset LIBOR $L\left(T_{j-1}, T_{j-1}\right)$ on a principal of 1 at each of the payment dates $T_j=\delta j, j=1,2, \ldots, n+1$. Show that the value of the swap is
$$
\delta K \sum_{j=1}^{n+1} B\left(0, T_j\right)-\delta \sum_{j=1}^{n+1} B\left(0, T_j\right) L\left(0, T_{j-1}\right) .
$$
Remark 10.7.1. The swap rate is defined to be the value of $K$ that makes the initial value of the swap equal to zero. Thus, the swap rate is
$$
K=\frac{\sum_{j=1}^{n+1} B\left(0, T_j\right) L\left(0, T_{j-1}\right)}{\sum_{j=1}^{n+1} B\left(0, T_j\right)}
$$