HELP ASAP PLZ A student is given that y varies directly with x^2 and that x = 2 when y = 8. Correct the student’s claim that x = 3 when y = 9 then. Explain your reasoning.

Question

asked Mar 1, 2020 53.3k views

1 Answer

Taskmaster · Answer 1 · 2020-03-04T22:14:03+0000

Answer:

see explanation

Explanation:

Given that y varies directly with x² then the equation relation them is

y = kx² ← k is the constant of variation

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

k =
(y)/(x^(2) ) =
(8)/(4) = 2

y = 2x² ← equation of variation

When y = 9, then

2x² = 9 ( divide both sides by 2 )

x² =
(9)/(2) = 4.5 ( take the square root of both sides )

x =
√(4.5) ≈ 2.12 ≠ 3