Use Simpson's rule to find the arclength of the curve LaTeX:  \displaystyle f(x)=\ln{\left(x \right)} on LaTeX:  \displaystyle (2,4) with LaTeX:  \displaystyle n=36 .

LaTeX:  \displaystyle \Delta x = \frac{ 4 - 2 }{ 36 } . LaTeX:  \displaystyle x_i = a +i\Delta x = 2 + i \frac{1}{18} 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 = 2 + (2k-1)\cdot \frac{1}{18} for LaTeX:  \displaystyle k=1 to LaTeX:  \displaystyle k =18 and LaTeX:  \displaystyle x_j = 2 + (2j)\cdot \frac{1}{18} for LaTeX:  \displaystyle j=1 to LaTeX:  \displaystyle j =17 . LaTeX:  \displaystyle f(2) +f(4)+4\sum_{k=1}^{18}f\left(\frac{k}{9} + \frac{35}{18}\right) + 2\sum_{j=1}^{17}f\left(\frac{j}{9} + 2\right) . The value is LaTeX:  \displaystyle 2.1208