The answer is a= -4.181818
The area of a circle in terms of the circle's radius

is

Differentiating both sides with respect to

, you get
Answer:
<h2>17.5</h2>
Step-by-step explanation:

This is your answer :))
Answer:
1/2
Step-by-step explanation:
since 10petrols=1 oil
therefore 5petrols=1/2
Answer:
44.5 yards
Step-by-step explanation:
Start with the formula of the circumference of a circle.
C = πd
Now all you have to do is plug in the numbers.
279.46 = (3.14)d
Divide both sides by 3.14
d = 89
But since you're finding the radius, you have to divide the diameter by 2.
89/2 = 44.5