Question

y is directly proportional to the positive square root of( x+2)² when x = 8 y= 250 find y when x = 4​

Answer 1

150

Explanation:

Since y is directly proportional to sqrt((x+2)^2), there is a constant,k, such that

y=ksqrt((x+2)^2)

We are given a pair (x,y) in this relation. Let's plug in (8,250 ) to find k.

250=ksqrt((8+2)^2)

250=ksqrt((10)^2)

250=k10

250/10=k

25=k

So for any pair (x,y) we have the relation y=25((x+2)^2).

We are asked to find y when x=4.

y=25((4+2))^2

y=25(6)

y=150

Test to see if y is proportional to sqrt((x+2)^2)

For the given points: 250/150=10/6

The equation is true so we're great.