Answer: A. 
B. A'(5) = 1.76 cm/s
Step-by-step explanation: <u>Rate</u> <u>of</u> <u>change</u> measures the slope of a curve at a certain instant, therefore, rate is the derivative.
A. Area of a circle is given by

So to find the rate of the area:


Using 

Then
![\frac{dA}{dt}=2.\pi.r.[\frac{726}{(t+11)^{3}}]](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%3D2.%5Cpi.r.%5B%5Cfrac%7B726%7D%7B%28t%2B11%29%5E%7B3%7D%7D%5D)
![\frac{dA}{dt}=2.\pi.[3-\frac{363}{(t+11)^{2}}].\frac{726}{(t+11)^{3}}](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%3D2.%5Cpi.%5B3-%5Cfrac%7B363%7D%7B%28t%2B11%29%5E%7B2%7D%7D%5D.%5Cfrac%7B726%7D%7B%28t%2B11%29%5E%7B3%7D%7D)
Multipying and simplifying:

The rate at which the area is increasing is given by expression
.
B. At t = 5, rate is:




At 5 seconds, the area is expanded at a rate of 1.76 cm/s.
Answer:
? = 57
Step-by-step explanation:
Since this is a right triangle, we can use trig functions
cos ? = adj/ hyp
cos ? = 14/26
Taking the inverse cos of each side
cos ^-1 ( cos ?) = cos ^-1 ( 14/26)
? = 57.42102961
To the nearest degree
? = 57
Answer:
The ordered pairs for 1 and 3 are:
(1,2) (3,8)
Now use the slope formula:
(y2-y1)/(x2-x1)
(8-2)/(3-1)= 6/2 = 3
Step-by-step explanation:
Answer:
The italian goalie: 85.7%
Step-by-step explanation:
17 / 20 = 85% (Russian)
12 / 14 = 85.7% (Italian)
The original price would be $58.75