Question

Y is inversely proportional to x2. When y =10, x = 2, what is y
when x = 10?

Answer 1

Answer:

$\dfrac25$

Step-by-step explanation:

$y \propto \dfrac{1}{x^2} \implies y=\dfrac{k}{x^2} \ \ \ \textsf{where k is some constant}$

when y = 10 and x  =2:

$\implies 10=\dfrac{k}{2^2}$

$\implies k=40$

Therefore,

$\implies y=\dfrac{40}{x^2}$

when x=10:

$\implies y=\dfrac{40}{10^2}=\dfrac{40}{100}=\dfrac25$