Yes, I forgot to equate it to zero. I barely remember my Calc days (been a decade now) when I was introduced to Implicitly defined functions (from Implicit differentiation). So I wasn't even sure I how to put it or would I just make a fool of myself.

About the problem, I just assumed that there was just an operation to ask W|A to put an expression to a uuser-provided-standard form.

I'm pertaining to implicitly defined functions, like usual, taking f(x) = y. So what I'm asking for is if I could ask Wolfram|Alpha if it can isolate the expression for f(x)/x. In my example:

y/x = 3/4x +/- sqrt(x^3 - 87/4)/x

So not exactly the derivative, but the slope from the point of origin.