Question 970536
<i>z varies jointly with x and y and inversely with the square of t.</i>


{{{z=k(xy/t^2)}}}


That was "really...fast" help, as you asked.


The function you are looking for needs precise information.  As given or asked so far, it is not understandable what you want or mean by f(y).  Give the exact  complete problem description, word-for-word.