Verified answer

It's easier to find an identity if you get rid of that inversion. So first multiply everything by Fxy.

Fxy(1/x + 1/y) = Fxy(1/F)

F(xy/x + xy/y) = xy(F/F)

F(y + x) = xy

Now you're asked to put everything in y= format. So break apart every term that has a y into y times f(C, x) form (in other words, y times terms that only contain a constant or x), like this:

y(F) + Fx = y(x)

Now it's very easy to turn it into a function in terms of y.

y(F) + Fx - Fx = y(x) - Fx

y(F) = y(x) - Fx

y(F) - y(x) = y(x) - y(x) - Fx

y(F) - y(x) = -Fx

y(F - x) = -Fx

y(F - x) / (F - x) = -Fx / (F - x)

y = -Fx / (F - x)

Now for B and C, draw up some values for X in a table. For x, you should pick:

* a very large negative number (between negative infinity and -5)

* -1

* a very small negative number (between -1 and 0)

* zero

* a very small positive number (between 0 and 1)

* 1

* a very large positive number (between 5 and infinity)

And just look at what you get for y when you plug those into the equation.