Given:


To find:
The value of
.
Solution:
We have,
![[\because d(t)=80t]](https://tex.z-dn.net/?f=%5B%5Cbecause%20d%28t%29%3D80t%5D)

Now,
![[\because C(d)=0.09d]](https://tex.z-dn.net/?f=%5B%5Cbecause%20C%28d%29%3D0.09d%5D)

Therefore, the value of
is 72.
Answer is 34.96$ for the final cost.
Assuming you mean the central angle, semicircles have central angles of
.
Answer:
Last on is the answer!! (The relation is a function, and the range is (-2,-1, 1, 3, 4). Hope this helps:)