Question

Write an equation that describes the following relationship: y varies inversely as the fourth power of u and when x = 2,y=7.y =

Answer 1

Given:

y varies inversely as the fourth power of x

For the inversely forth power of x is:

$y\propto\frac{1}{x^4}$

So the value of y is:

$y=\frac{k}{x^4}$

where,

k = constent

so the value of k is x=2 and y = 7.

$\begin{gathered} y=\frac{k}{x^4} \\ 7=\frac{k}{2^4} \\ k=7\times2^4 \\ k=7\times16 \\ k=112 \end{gathered}$

Then the function is:

$y=\frac{112}{x^4}$