The surface area, a, of a sphere in terms of its radius, r, is given by a(r) = 4πr2. express r as a function of a.

r =√ ( A / 4π )

given A = 4πr² ( isolate r² by dividing both sides by 4π )

A / 4π = r² ( take the square root of both sides )

r =√( A / 4π )

-1, -2, -3, -4, -6

step-by-step explanation:

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.