<span>Width = 6
Length = 30
We know the perimeter of a rectangle is simply twice the sum of it's length and width. So we have the expression:
72 = 2*(L + W)
And since we also know for this rectangle that it's length is 6 more than 4 times it's width, we have this equation as well:
L = 6 + 4*W
So let's determine what the dimensions are. Since we have a nice equation that expresses length in terms of width, let's substitute that equation into the equation we have for the perimeter and solve. So:
72 = 2*(L + W)
72 = 2*(6 + 4*W + W)
72 = 2*(6 + 5*W)
72 = 12 + 10*W
60 = 10*W
6 = W
So we now know that the width is 6. And since we have an expression telling us the length when given the width, we can easily determine the length. So:
L = 6 + 4*W
L = 6 + 4*6
L = 6 + 24
L = 30
And now we know the length as well.</span>
I think the rate is decreasing from:
(-infinity, ln9/3)
Answer:
9/20 pages per minute.
Step-by-step explanation:
Check the picture below.
now, let's keep in mind that, the vertex is half-way between the focus point and the directrix, it's a "p" distance from each other.
since this horizontal parabola is opening to the left-hand-side, "p" is negative, notice in the picture, "p" is 2 units, and since it's negative, p = -2.
its vertex is half-way between those two guys, so that puts the vertex at (-5, 3)
![\bf \textit{parabola vertex form with focus point distance} \\\\ \begin{array}{llll} 4p(x- h)=(y- k)^2 \\\\ 4p(y- k)=(x- h)^2 \end{array} \qquad \begin{array}{llll} vertex\ ( h, k)\\\\ p=\textit{distance from vertex to }\\ \qquad \textit{ focus or directrix} \end{array} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \begin{cases} h=-5\\ k=7\\ p=-2 \end{cases}\implies 4(-2)[x-(-5)]=[y-7]^2 \\\\\\ -8(x+5)=(y-7)^2\implies x+5=\cfrac{(y-7)^2}{-8}\implies \boxed{x=-\cfrac{1}{8}(y-7)^2-5}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bparabola%20vertex%20form%20with%20focus%20point%20distance%7D%20%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7Bllll%7D%204p%28x-%20h%29%3D%28y-%20k%29%5E2%20%5C%5C%5C%5C%204p%28y-%20k%29%3D%28x-%20h%29%5E2%20%5Cend%7Barray%7D%20%5Cqquad%20%5Cbegin%7Barray%7D%7Bllll%7D%20vertex%5C%20%28%20h%2C%20k%29%5C%5C%5C%5C%20p%3D%5Ctextit%7Bdistance%20from%20vertex%20to%20%7D%5C%5C%20%5Cqquad%20%5Ctextit%7B%20focus%20or%20directrix%7D%20%5Cend%7Barray%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20h%3D-5%5C%5C%20k%3D7%5C%5C%20p%3D-2%20%5Cend%7Bcases%7D%5Cimplies%204%28-2%29%5Bx-%28-5%29%5D%3D%5By-7%5D%5E2%20%5C%5C%5C%5C%5C%5C%20-8%28x%2B5%29%3D%28y-7%29%5E2%5Cimplies%20x%2B5%3D%5Ccfrac%7B%28y-7%29%5E2%7D%7B-8%7D%5Cimplies%20%5Cboxed%7Bx%3D-%5Ccfrac%7B1%7D%7B8%7D%28y-7%29%5E2-5%7D)
Reflection across the line y=x simply swaps the x and y coordinates.
K'(-2, -5), A'(1, -4), I'(-1, 0), J'(-4, -2)
