Questioning my use of "in question"

Question

I just found myself writing some documentation that uses "in question," but then I questioned whether what I wrote makes sense. The context is a document that describes the numerical solution of different classes of various initial value ordinary differential equation (ODE for short), with the assumption that the reader of the document will know what that gobbledygook means.

Here's what I wrote:

[This module] supports a number of classes of numerical integration problems, characterized by the nature of the underlying ODE: ...

• Problems such as propagating the translational state of a vehicle.
  This class of problems involves propagating a vector quantity and its time derivative based on the second time derivative of the vector quantity in question.

For example, think of advancing position and velocity over time given a magical function that computes acceleration (but the problem is more generic than that).

Is my use of in question here grammatically correct and also clear, or should I rewrite and use some other phraseology?

Answer 1

It's correct and clear, referring back to the aforementioned vector, but you could also use this vector or the same vector. In question can suggest an effort to determine the vector, but it reads fine to me.

Answer 2

"In question" looks fine. But if you're looking for something else, then instead of

"vector quantity in question"

I would suggest:

"dedicated vector quantity"

If that helps you.