Question

Y is inversely proportional to x3. When x = 2, y = 0.5 .
Find y in terms of x.

Answer 1

y =
`(4)/(x^3)`

Explanation:

given y is inversely proportional to x³ then the equation relating them is

y =
`(k)/(x^3)` ← k is the constant of proportion

to find k use the condition x = 2 , y = 0.5 , then

0.5 =
`(k)/(2^3)` =
`(k)/(8)` ( multiply both sides by 8 to clear the fraction )

0.5 × 8 = k , that is

k = 4

y =
`(4)/(x^3)` ← equation of proportion