Area=pi times radiius^2
radius=diameter/2
diamter=5
radius=5/2=2.5
pi=3.14 aprox
area=3.14 times 2.5^2
area=3.14 times 6.25
area=19.625 ft^2
round
19.6 round up
20
the answer is 20 ft^2
Answer:
The diameter decreases at a rate of 0.143cm/min when it is of 10 cm.
Step-by-step explanation:
Surface area of an snowball:
An snowball has spherical format. The surface area of an sphere is given by:

In which d is the diameter of the sphere.
In this question:
We need to differentiate S implicitly in function of time. So

Surface area decreases at a rate of 9 cm2/min
This means that 
At which the diameter decreases when the diameter is 10 cm?
This is
when
. So




Area in cm², so diameter in cm.
The diameter decreases at a rate of 0.143cm/min when it is of 10 cm.
Answer:
2x² - 3x + 6 = 0
a = 2 b = -3 c = 6
delta = b² - 4ac = 9 - 4.2.6 = -39
