Suppose my function `d` below can output the same answer for a different combination of its two input values.

For example, to output `0.8164966`, one can input `d(2, 12)` or similarly `d(1, 3)` and many more combinations of the two input values.

**Question** Is there a way to get **just one possible** pair of input values IF I provide the desired output `d`?

For example, if I desire to have a `d = 0.8164966`, can R give me just `1 and 3` as one pair of possible input values that lead to a `d = 0.8164966`?

**NOTE:** I'm asking how to solve for ***only one pair of possible (there are many) input values*** given any `d` (the output).

```
d <- function(mean_dif, Vmax) mean_dif/sqrt(Vmax/2)

d(2, 12)  # 0.8164966
d(1, 3)   # 0.8164966

```