Question

Find the variation and an equation of variation where y varies inversely as x and y= 0.4 when x= 0.8

Answer 1

Hi!

The words "y varies inversely as x" automatically means we can write:

$y=\cfrac{k}{x}$

Note that this is a fraction because it said "inversely". If it had said "jointly" or "directly", it would have been $y=kx$.

Now, we plug in the given values to solve for k.

We are given:

$y = 0.4$

$x = 0.8$

Plug those in and we have:

$0.4=\cfrac{k}{0.8}$

Multiply both sides by $0.8$:

$0.32=k$

Now, with the value of $k$ solved for, we put it back into the original equation, and that's your answer:

$y=\cfrac{0.32}{x}$

For a similar problem, see:

https://brainly.com/question/2315806