Variation Functions-1

Question

If y varies inversely as x, and y = 7 when x = 8, then find y when x = 4. Just type the number. If the answer is not an integer, then write it as a fraction in simplest form, with a slash (/) between the numerator and the denominator.

Answer 1

The equation for y varying inversely with x is xy=k, or y=k/x.

We can find the constant of variation by using y=7 when x=8 by k=xy.

k=xy

k=(8)(7)=54

Now, with k=54 and x=4 we can solve for y:

y=k/x

y=54/4

y=27/2

Hope this helps!

Answer 2

In this case if y varies inversely with x we multiply them to get a product.

So, if y=7 and x=8 then yx=56

then if x=4 we can set it up as follows 4y=56 and y=56/4 or 14