The answer to the question is A
Answer:
B
Step-by-step explanation:
In the standard form of the equation
![\\ \ f(t)=Acos[b(t\pm c)]+k\\ \\](https://tex.z-dn.net/?f=%20%5C%5C%20%5C%20f%28t%29%3DAcos%5Bb%28t%5Cpm%20c%29%5D%2Bk%5C%5C%20%5C%5C%20)
The middle line =k
For our given problem
f(t) = 40cos (80t + 20)
On comparison we get k=0
Hence middle line=0
Answer:
![\pi x^2-8\pi x+16\pi](https://tex.z-dn.net/?f=%5Cpi%20x%5E2-8%5Cpi%20x%2B16%5Cpi)
Step-by-step explanation:
To find the area of the inner circle, we need to find its radius. Here, we can write the radius as 4 - x. Now, we can use the formula
:
A =
* ![(4-x)^2](https://tex.z-dn.net/?f=%284-x%29%5E2)
We can expand the square:
A = ![\pi *(16-8x+x^2)=\pi x^2-8\pi x+16\pi](https://tex.z-dn.net/?f=%5Cpi%20%2A%2816-8x%2Bx%5E2%29%3D%5Cpi%20x%5E2-8%5Cpi%20x%2B16%5Cpi)
Thus, the polynomial is
.
Hope this helps!