By the way, it's pi, not pie. just wanted you to know as you may lose marks in tests for spelling (but i may be wrong)
we know circumference is pi multiplied by the diameter.
the diameter is 2x the radius
we can re-arrange the first fact to get:
diameter (or 2x radius) = circumference divided by pi.
since the circumference is 24pi we can cancel off pi from the circumference (24pi) and pi.
now we have the diameter = 24
since the diameter is 2x the radius you divide both sides by 2 and get:
radius=12cm
Answer:
Step-by-step explanation:
Answer:
≈ 12.57 units squared
Step-by-step explanation:
The area of a circle is denoted by: 
, where r is the radius.
Remember that diameter is twice the radius, so since the diameter equals 4, we know that the radius r = 4/2 = 2.
Now, plug this in: 
We can round 4pi to 12.57 units squared.
Hope this helps!
9514 1404 393
Answer:
8000π mm^3/s ≈ 25,133 mm^3/s
Step-by-step explanation:
The rate of change of volume is found by differentiating the volume formula with respect to time.
V = 4/3πr^3
V' = 4πr^2·r'
For the given numbers, this is ...
V' = 4π(20 mm)^2·(5 mm/s) = 8000π mm^3/s ≈ 25,133 mm^3/s
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<em>Additional comment</em>
By comparing the derivative to the area formula for a sphere, you see that the rate of change of volume is the product of the area and the rate of change of radius. This sort of relationship will be seen for a number of different shapes.
Answer:
the turning point is (-2,-1)
i dont know the turning point but i hope this helps
Step-by-step explanation:
