Math 181 Miniproject 7: The Shape of a Graph.md --- --- tags: MATH 181 --- Math 181 Miniproject 7: The Shape of a Graph === **Overview:** In this miniproject you will be using the techniques of calculus to find the behavior of a graph. **Prerequisites:** The project draws heavily from the ideas of Chapter 1 and $2.8$ together with ideas and techniques of the first and second derivative tests from $3.1$. --- :::info We are given the functions $$ f(x)=\frac{12x^2-16}{x^3},\qquad f'(x)=-\frac{12(x^2-4)}{x^4},\qquad f''(x)=\frac{24(x^2-8)}{x^5}. $$ The questions below are about the function $f(x)$. Answer parts (1) through (10) below. If the requested feature is missing, then explain why. Be sure to include the work/test that you used to rigorously reach your conclusion. It is not sufficient to refer to the graph. (1) State the function's domain. ::: (1) The domain of the function f(x) is $(-infinty,-1.55]U[1.55, infinity)$. :::info (2) Find all $x$- and $y$-intercepts. ::: (2)$f(x)=\frac{12x^2-16}{x^3}$, are when x=0 and when f(0). Which are (square root 4/3, 0) and (-square root 4/3, 0), which were solved on problems 3 and 4. :::info (3) Find all equations of horizontal asymptotes. ::: (3)The horizontal asypmtotes of f(x) are when x=0 because it makes the denominator undefined. $f(0)=\frac{12(0)^2-16}{(0)^3}=undefined$ :::info (4) Find all equations of vertical asymptotes. ::: (4)$f(x)=\frac{12x^2-16}{x^3}$ set f(x)=0, $0=\frac{12x^2-16}{x^3}$ $0={12x^2-16}$ $16=12x^2$ $16/12=x^2$ +-square root(4/3)=x therefore the vertical asymptotes are at +-sqrt(4/3) :::info (5) Find the interval(s) where $f$ is increasing. ::: (5)Using the inflection test on problem 9 I was able to draw the conclusions of f(x) is concave up on the intervals (-square root 8, 0) and (square root 8, infinity) since the second derivitive test will show inflection points as well as concavitiy, :::info (6) Find the $x$-value(s) of all local maxima. (Find exact values, and not decimal representations) ::: (6) The local maxima is f(x)=2 ![](https://i.imgur.com/MZIBQf4.jpg) :::info (7) Find the $x$-value(s) of all local minima. (Find exact values, and not decimal representations) ::: (7) The local minima is f(x)=-2, work shown in problem 6. :::info (8) Find the interval(s) on which the graph is concave downward. ::: (8)Using the inflection test on problem 9 I was able to draw the conclusions of f(x) is concave down on the intervals (-infinity, square root 8) since the second derivitive test will show inflection points as well as concavitiy, :::info (9) State the $x$-value(s) of all inflection points. (Find exact values, and not decimal representations) ::: (9)![](https://i.imgur.com/aeBm2CI.jpg) :::info (10) Include a sketch of the graph of $y=f(x)$. Plot the different segments of the graph using the color code below. * **blue:** $f'>0$ and $f''>0$ * **red:** $f'<0$ and $f''>0$ * **black:** $f'>0$ and $f''<0$ * **gold:** $f'<0$ and $f''<0$ (In Desmos you could restrict the plot $y=f(x)$ on the interval $[2,3]$ by typing $y=f(x)\{2\le x\le 3\}$.) Be sure to set the bounds on the graph so that the features of the graph that you listed above are easy to see. ::: (10) <iframe src="https://www.desmos.com/calculator/mdiarbvsi7?embed" width="500px" height="500px" style="border: 1px solid #ccc" frameborder=0></iframe> --- To submit this assignment click on the Publish button ![Publish button icon](https://i.imgur.com/Qk7vi9V.png). Then copy the url of the final document and submit it in Canvas.