Question

Y is directly proportional to x^3

Answer 1

Answer:

$64y = 17 {x}^{3}$

Step-by-step explanation:

$y \: \alpha \: {x}^{3} ....(given) \\ \therefore \: y = k {x}^{3} .. (1)\\ (k =arbitrary \:constant) \\when \: x = 4, \: \: y = 17, \:k =? \\ 17 = k {(4)}^{3} \\ 17 = 64k \\ k = \frac{17}{64} \\ plug \: k =\frac{17}{64} \: in \: equation \: (1) \\ y = \frac{17}{64} {x}^{3} \\ 64y = 17 {x}^{3}$

Answer 2

Answer:

y~x^3

Step-by-step explanation:

y~x^3

17~kx^3

where k is a constant

making k the subject

k=17/x^3

substitute x=4

k=17/4^3

k =17/64

Therefore the equation connecting y and x is

y=17/64x^3