D. f(x)= x*-9x^o+2x^2-4x+10
THe area of the whole circle is pi r^2 = 6^2 * pi = 36pi
There are 360 degrees in a crcle so this sectors area i (30/360) *36pi
= 3 pi
Step-by-step explanation:

Use the identity

on the left side.
![\dfrac{1 - \cos [2(\frac{\pi}{4} - \alpha)]}{2} = \frac{1}{2}(1 - \sin 2\alpha)](https://tex.z-dn.net/?f=%20%5Cdfrac%7B1%20-%20%5Ccos%20%5B2%28%5Cfrac%7B%5Cpi%7D%7B4%7D%20-%20%5Calpha%29%5D%7D%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%281%20-%20%5Csin%202%5Calpha%29%20)

Now use the identity

on the left side.


Find the volume of the rectangular prism.
V = lwh
V = (9)(16)(4)
V = 756 ft^3
Convert to cubic yards:
1 ft^3 = 0.037037037 yd^3
756 * 0.037037037 = 28
So there are 28 cubic yards of dirt he needs.
Multiply this to 25 to find the total cost of the dirt:
28 * 25 = 700
So the project will cost $700