In order to find the Riemann Sum of a given function, we need to approximate the area under the line or curve resulting from the function using rectangles spaced along equal sub-intervals of a given interval. Since we have an interval  \(\displaystyle [0,4]\) divided into \(\displaystyle 4\) sub-intervals, we'll be using rectangles with vertices at \(\displaystyle x=0,1,2,3,4\).

To approximate the area under the curve, we need to find the areas of each rectangle in the sub-intervals. We already know the width or base of each rectangle is \(\displaystyle b=1\) because the rectangles are spaced \(\displaystyle 1\) unit apart. Since we're looking for the Right Riemann Sum of \(\displaystyle y=\frac{5}{x}\), we want to find the heights  of each rectangle by taking the values of each rightmost function value on each sub-interval, as follows:

\(\displaystyle f(4)=\frac{5}{4}\)

\(\displaystyle f(3)=\frac{5}{3}\)

\(\displaystyle f(2)=\frac{5}{2}\)

\(\displaystyle f(1)=\frac{5}{1}=5\)

Putting it all together, the Right Riemann Sum is

\(\displaystyle A=bh=1(\frac{5}{4}+\frac{5}{3}+\frac{5}{2}+5)=\frac{15}{12}+\frac{20}{12}+\frac{30}{12}+\frac{60}{12}=\frac{125}{12}\).

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{1}^{15.8}(-15sin(14e^{(4x)}))dx\\&\text{So the interval is }[1,15.8]\text{ the subintervals have length }\frac{15.8-(1)}{4}=\frac{37}{10}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[\frac{47}{10},\frac{42}{5},\frac{121}{10},\frac{79}{5}]\\&\int_{1}^{15.8}(-15sin(14e^{(4x)}))dx=\frac{37}{10}[(-15sin(14e^{(4(\frac{47}{10}))}))+(-15sin(14e^{(4(\frac{42}{5}))}))+(-15sin(14e^{(4(\frac{121}{10}))}))+(-15sin(14e^{(4(\frac{79}{5}))}))]\\&\int_{1}^{15.8}(-15sin(14e^{(4x)}))dx=20.79\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{4}^{14}(-8sin(12e^{(x)}))dx\\&\text{So the interval is }[4,14]\text{ the subintervals have length }\frac{14-(4)}{4}=\frac{5}{2}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[\frac{13}{2},9,\frac{23}{2},14]\\&\int_{4}^{14}(-8sin(12e^{(x)}))dx=\frac{5}{2}[(-8sin(12e^{((\frac{13}{2}))}))+(-8sin(12e^{((9))}))+(-8sin(12e^{((\frac{23}{2}))}))+(-8sin(12e^{((14))}))]\\&\int_{4}^{14}(-8sin(12e^{(x)}))dx=-17.23\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{0}^{6}(5x - 1000sin(3x)^{2})dx\\&\text{So the interval is }[0,6]\text{ the subintervals have length }\frac{6-(0)}{4}=\frac{3}{2}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[\frac{3}{2},3,\frac{9}{2},6]\\&\int_{0}^{6}(5x - 1000sin(3x)^{2})dx=\frac{3}{2}[(5(\frac{3}{2}) - 1000sin(3(\frac{3}{2}))^{2})+(5(3) - 1000sin(3(3))^{2})+(5(\frac{9}{2}) - 1000sin(3(\frac{9}{2}))^{2})+(5(6) - 1000sin(3(6))^{2})]\\&\int_{0}^{6}(5x - 1000sin(3x)^{2})dx=-3390.69\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{-4}^{-1.6}(15cos(12sin(6x)) + 5x^{3})dx\\&\text{So the interval is }[-4,-1.6]\text{ the subintervals have length }\frac{-1.6-(-4)}{3}=\frac{4}{5}\end{align*}\)

\(\displaystyle \begin{align*}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[-\frac{16}{5},-\frac{12}{5},-\frac{8}{5}]\\&\int_{-4}^{-1.6}(15cos(12sin(6x)) + 5x^{3})dx\approx\frac{4}{5}[(15cos(12sin(6(-\frac{16}{5}))) + 5(-\frac{16}{5})^{3})+(15cos(12sin(6(-\frac{12}{5}))) + 5(-\frac{12}{5})^{3})+(15cos(12sin(6(-\frac{8}{5}))) + 5(-\frac{8}{5})^{3})]\\&\int_{-4}^{-1.6}(15cos(12sin(6x)) + 5x^{3})dx\approx-208.73\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{0}^{13.6}(2x + 4sin(3tan(5x)))dx\\&\text{So the interval is }[0,13.6]\text{ the subintervals have length }\frac{13.6-(0)}{4}=\frac{17}{5}\end{align*}\)

\(\displaystyle \begin{align*}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[\frac{17}{5},\frac{34}{5},\frac{51}{5},\frac{68}{5}]\\&\int_{0}^{13.6}(2x + 4sin(3tan(5x)))dx\approx\frac{17}{5}[(2(\frac{17}{5}) + 4sin(3tan(5(\frac{17}{5}))))+(2(\frac{34}{5}) + 4sin(3tan(5(\frac{34}{5}))))+(2(\frac{51}{5}) + 4sin(3tan(5(\frac{51}{5}))))+(2(\frac{68}{5}) + 4sin(3tan(5(\frac{68}{5}))))]\\&\int_{0}^{13.6}(2x + 4sin(3tan(5x)))dx\approx214.27\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{-4}^{7.1}(4x - 15sin(13x^{2}))dx\\&\text{So the interval is }[-4,7.1]\text{ the subintervals have length }\frac{7.1-(-4)}{3}=\frac{37}{10}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[-\frac{3}{10},\frac{17}{5},\frac{71}{10}]\\&\int_{-4}^{7.1}(4x - 15sin(13x^{2}))dx\approx\frac{37}{10}[(4(-\frac{3}{10}) - 15sin(13(-\frac{3}{10})^{2}))+(4(\frac{17}{5}) - 15sin(13(\frac{17}{5})^{2}))+(4(\frac{71}{10}) - 15sin(13(\frac{71}{10})^{2}))]\\&\int_{-4}^{7.1}(4x - 15sin(13x^{2}))dx\approx74.37\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{-1}^{15}(3x + 5sin(2e^{(2x)}))dx\\&\text{So the interval is }[-1,15]\text{ the subintervals have length }\frac{15-(-1)}{4}=4\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[3,7,11,15]\\&\int_{-1}^{15}(3x + 5sin(2e^{(2x)}))dx\approx4[(3(3) + 5sin(2e^{(2(3))}))+(3(7) + 5sin(2e^{(2(7))}))+(3(11) + 5sin(2e^{(2(11))}))+(3(15) + 5sin(2e^{(2(15))}))]\\&\int_{-1}^{15}(3x + 5sin(2e^{(2x)}))dx\approx431.64\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{3}^{4.8}(4x + 16cos(13e^{(3x)}))dx\\&\text{So the interval is }[3,4.8]\text{ the subintervals have length }\frac{4.8-(3)}{3}=\frac{3}{5}\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[\frac{18}{5},\frac{21}{5},\frac{24}{5}]\\&\int_{3}^{4.8}(4x + 16cos(13e^{(3x)}))dx\approx\frac{3}{5}[(4(\frac{18}{5}) + 16cos(13e^{(3(\frac{18}{5}))}))+(4(\frac{21}{5}) + 16cos(13e^{(3(\frac{21}{5}))}))+(4(\frac{24}{5}) + 16cos(13e^{(3(\frac{24}{5}))}))]\\&\int_{3}^{4.8}(4x + 16cos(13e^{(3x)}))dx\approx34.93\end{align*}\)

\(\displaystyle \begin{align*}&\text{A Riemann sum integral approximation over an interval [a, b]}\\&\text{with n subintervals follows the form:}\\&\int_a^b f(x)dx \approx \frac{b-a}{n}(f(x_1)+f(x_2)+...+f(x_n))\\&\text{It is essentially a sum of n rectangles, each with a base of}\\&\text{length :}\frac{b-a}{n}\text{ and variable heights :}f(x_i)\text{, which depend on the function value at }x_i\\&\text{We're asked to approximate}\int_{-5}^{15}(4x + 18sin(tan(5x)))dx\\&\text{So the interval is }[-5,15]\text{ the subintervals have length }\frac{15-(-5)}{4}=5\\&\text{and since we are using the *right*point of each interval, the x-values are:}\\&[0,5,10,15]\\&\int_{-5}^{15}(4x + 18sin(tan(5x)))dx\approx5[(4(0) + 18sin(tan(5(0))))+(4(5) + 18sin(tan(5(5))))+(4(10) + 18sin(tan(5(10))))+(4(15) + 18sin(tan(5(15))))]\\&\int_{-5}^{15}(4x + 18sin(tan(5x)))dx\approx527.09\end{align*}\)