Question

0.2

y is inversely proportional to V1+x.
When x=8, y = 2.
Find y when x = 15.

Please help me with this real quick!

Answer 1

y = 1.5

Explanation:

Given y is inversely proportional to
`√(1+x)` , then the equation relating them is

y =
`(k)/(√(1+x) )` ← k is the constant of variation

To find k use the condition when x = 8, y = 2 , then

2 =
`(k)/(√(1+8) )` =
`(k)/(√(9) )` =
`(k)/(3)` ( multiply both sides by 3 )

6 = k

y =
`(6)/(√(1+x) )` ← equation of variation

When x = 15, then

y =
`(6)/(√(1+15) )` =
`(6)/(√(16) )` =
`(6)/(4)` = 1.5