Given the partition $\{0,\,\frac{\pi}{4},\,\frac{\pi}{2},\,\frac{3\pi}{4},\,\pi\}$, and points $\bar{x}_1=\frac{\pi}{8}$, $\bar{x}_2=\frac{3\pi}{8}$, $\bar{x}_3=\frac{5\pi}{8}$, and $\bar{x}_4=\frac{7\pi}{8}$; find $R(P)$ for $\int_0^{\pi}\sin(x)\,dx$.

Problem: 

Given the partition $\{0,\,\frac{\pi}{4},\,\frac{\pi}{2},\,\frac{3\pi}{4},\,\pi\}$, and points $\bar{x}_1=\frac{\pi}{8}$, $\bar{x}_2=\frac{3\pi}{8}$, $\bar{x}_3=\frac{5\pi}{8}$, and $\bar{x}_4=\frac{7\pi}{8}$; find the Riemann sum $R(P)$ for the integral $\int_0^{\pi}\sin(x)\,dx$.

Answer: 

2.05