Question

y is directly proportional to the square root of x, y is 75 and x is 100. find a formula linking x and y

Answer 1

y = 7.5
`√(x)`

Explanation:

given y is directly proportional to
`√(x)` then the equation relating them is

y = k
`√(x)` ← k is the constant of proportion

to find k use the condition y = 75 , x = 100 , then

75 = k
`√(100)` = 10k ( divide both sides by 10 )

7.5 = k

y = 7.5
`√(x)` ← equation of proportion