Answer:
![A = 640000\,yd^{2}](https://tex.z-dn.net/?f=A%20%3D%20640000%5C%2Cyd%5E%7B2%7D)
Step-by-step explanation:
Expression for the rectangular area and perimeter are, respectively:
![A (x,y) = x\cdot y](https://tex.z-dn.net/?f=A%20%28x%2Cy%29%20%3D%20x%5Ccdot%20y)
![3200\,yd = 2\cdot (x+y)](https://tex.z-dn.net/?f=3200%5C%2Cyd%20%3D%202%5Ccdot%20%28x%2By%29)
After some algebraic manipulation, area expression can be reduce to an one-variable form:
![y = 1600 -x](https://tex.z-dn.net/?f=y%20%3D%201600%20-x)
![A (x) = x\cdot (1600-x)](https://tex.z-dn.net/?f=A%20%28x%29%20%3D%20x%5Ccdot%20%281600-x%29)
The first derivative of the previous equation is:
![\frac{dA}{dx}= 1600-2\cdot x](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdx%7D%3D%201600-2%5Ccdot%20x)
Let the expression be equalized to zero:
![1600-2\cdot x=0](https://tex.z-dn.net/?f=1600-2%5Ccdot%20x%3D0)
![x = 800](https://tex.z-dn.net/?f=x%20%3D%20800)
The second derivative is:
![\frac{d^{2}A}{dx^{2}} = -2](https://tex.z-dn.net/?f=%5Cfrac%7Bd%5E%7B2%7DA%7D%7Bdx%5E%7B2%7D%7D%20%3D%20-2)
According to the Second Derivative Test, the critical value found in previous steps is a maximum. Then:
![y = 800](https://tex.z-dn.net/?f=y%20%3D%20800)
The maximum area is:
![A = (800\,yd)\cdot (800\,yd)](https://tex.z-dn.net/?f=A%20%3D%20%28800%5C%2Cyd%29%5Ccdot%20%28800%5C%2Cyd%29)
![A = 640000\,yd^{2}](https://tex.z-dn.net/?f=A%20%3D%20640000%5C%2Cyd%5E%7B2%7D)
BY USING MIDDLE TERM SPLITTING,
3y^2-(3y-2y)-2
(3y^2-3y)+(2y-2)
3y(y-1)+2(y-1)
(3y+2)(y-1)
HOPE THIS WILL HELP U
I think it’s 39 cuz we have to subtract it by 180(supplementary angles) plus the angle is an obtuse angle(meaning more than 0 but less than 90)
Answer:
4
Step-by-step explanation: