Answer:
Step-by-step explanation:
We have been given the formula of area of a circle and we are asked to write the formula of diameter in terms of the area of the circle.
![A=\pi r^2...(1)](https://tex.z-dn.net/?f=A%3D%5Cpi%20r%5E2...%281%29)
![d=2r...(2)](https://tex.z-dn.net/?f=d%3D2r...%282%29)
We will use substitution method to solve for d. From equation (2) we will get,
![\frac{d}{2}=\frac{2r}{2}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7B2%7D%3D%5Cfrac%7B2r%7D%7B2%7D)
![\frac{d}{2}=r](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7B2%7D%3Dr)
Upon substituting this value in equation (1) we will get,
![A=\pi (\frac{d}{2})^2](https://tex.z-dn.net/?f=A%3D%5Cpi%20%28%5Cfrac%7Bd%7D%7B2%7D%29%5E2)
![A=\pi *\frac{d^2}{4}](https://tex.z-dn.net/?f=A%3D%5Cpi%20%2A%5Cfrac%7Bd%5E2%7D%7B4%7D)
Let us multiply both sides of our equation 4.
![A*4=\pi *\frac{d^2}{4}*4](https://tex.z-dn.net/?f=A%2A4%3D%5Cpi%20%2A%5Cfrac%7Bd%5E2%7D%7B4%7D%2A4)
![4A=\pi *d^2](https://tex.z-dn.net/?f=4A%3D%5Cpi%20%2Ad%5E2)
Let us divide both sides of our equation by pi.
![\frac{4A}{\pi}=\frac{\pi *d^2}{\pi}](https://tex.z-dn.net/?f=%5Cfrac%7B4A%7D%7B%5Cpi%7D%3D%5Cfrac%7B%5Cpi%20%2Ad%5E2%7D%7B%5Cpi%7D)
![\frac{4A}{\pi}=d^2](https://tex.z-dn.net/?f=%5Cfrac%7B4A%7D%7B%5Cpi%7D%3Dd%5E2)
![d^2=\frac{4A}{\pi}](https://tex.z-dn.net/?f=d%5E2%3D%5Cfrac%7B4A%7D%7B%5Cpi%7D)
Let us take square root of both sides of our equation.
![d=\sqrt{\frac{4A}{\pi}}](https://tex.z-dn.net/?f=d%3D%5Csqrt%7B%5Cfrac%7B4A%7D%7B%5Cpi%7D%7D)
Therefore, the equation
represents the formula for diameter in terms of the area of the circle.
Answer:
-4, 2 i don't really know what to do
Step-by-step explanation:
Answer:
blurd po
Step-by-step explanation:
^_________^^_________^^_________^
Answer:
85
Step-by-step explanation:
2(-4)^2=32
-10(-4)=40
32+40+13=85