Question

Assume that a varies directly as b. What is the constant of proportionality if a = 8 when b = 2?

k = 16
k = 4
k=1/4
k=6

Answer 1

k = 4

Explanation:

Given that a varies directly as b then the equation relating them is

a = kb ← k is the constant of variation

To find k use the condition a = 8 when b = 2

k =
`(a)/(b)` =
`(8)/(2)` = 4

Answer 2

K = 4

Explanation:

Given that varies a directly as b then the equation relating them is

Simply implies that a is directly proportional to b, that is increase in a will cause increase in, and decrease in a will cause decrease in b, and vice versa, where k remains constant.

a α b

a = kb, where k is constant

To find k use the condition a = 8 when b = 2, we make k the subject of the formular

K = a/b

K = 8/2

K = 4