Area of shaded portion = area of circle 1 - circle 2
Pi r*2 - pi R*2 =
Pi (r*2 -R *2 ) = 9*2 - 5*2 = (pi)81- 25= 56 x 3 = 168
No, they are not equivalent. The first term, -4 1/2 equals 4 whole units and one half unit. All negative. So it’s like you have someone 4 and 1/2 dollars.
The second term, (-4)1/2 means multiplying -4 times 1/2. Doing the multiplication for this gives you -4/2. Solving the division here is -2. It’s taking away 1/2 dollar 4 times.
I hope this helped. Happy to answer any questions you have.
Answer:

Step-by-step explanation:
We are given that
Initially the difference between the cake's and the cooler's temperature ,a=50 degree Celsius

We have to find the function that gives the temperature difference in degrees Celsius D(t).
We know that

Substitute the values


This is required function that gives the temperature difference in degrees Celsius.
we can factor the whole thing:
(2sin(x) -1)(sin(x)+1) = 0.
Therefore, sin(x) = -1 and sin(x) = 1/2.
For the first one x = 3π/2 and the second is π/6 and 5π/6
So 3π/2, π/6 and 5π/6 are the solutions.
I do kind of have a problem with this because it doesn't mention if you should go over 360°. Otherwise, you have to add in an 2nπ into the equations like 3π/2 + 2nπ; 
but I don't know if that is necessary for you.
Answer:
17>n is the correct answer