Use Simpson's rule to find the arclength of the curve LaTeX:  \displaystyle f(x)=\cos{\left(x \right)} on LaTeX:  \displaystyle (3,4) with LaTeX:  \displaystyle n=28 .

LaTeX:  \displaystyle \Delta x = \frac{ 4 - 3 }{ 28 } . LaTeX:  \displaystyle x_i = a +i\Delta x = 3 + i \frac{1}{28} Using the 1,4,2,...,2,4,1 pattern the sum can be written as LaTeX:  \displaystyle x_i can be written split into the even and odd terms. LaTeX:  \displaystyle x_k = 3 + (2k-1)\cdot \frac{1}{28} for LaTeX:  \displaystyle k=1 to LaTeX:  \displaystyle k =14 and LaTeX:  \displaystyle x_j = 3 + (2j)\cdot \frac{1}{28} for LaTeX:  \displaystyle j=1 to LaTeX:  \displaystyle j =13 . LaTeX:  \displaystyle f(3) +f(4)+4\sum_{k=1}^{14}f\left(\frac{k}{14} + \frac{83}{28}\right) + 2\sum_{j=1}^{13}f\left(\frac{j}{14} + 3\right) . The value is LaTeX:  \displaystyle 1.0846