How to describe I am one of only two people on the team with engineering background

Question

I am trying to write a self-motivation letter to apply a position, but I am not sure what is the better way to describe one of my past experience. I am trying to describe that there are only two people on a competition team with engineering background and I am one of them with engineering background.

Originally description I wrote was

As one of only-two people with engineering background on the team, I taught how to model our system based on differential equations by myself and learnt how to collaborate with other team members from biomedical disciplines.

Answer 1

Frankly, if you needed to teach yourself modeling with differential equations, that makes your engineering background look rather sketchy. So I would not write it like that. How about "In our team, as one of two members with an engineering background I was responsible for creating the differential equation model of our system in collaboration with our team members with a biomedical background."

Answer 2

I am not sure what a "self-motivation" letter is.

If it is to be seen by anyone other than yourself, I strongly advise you to avoid the word "only" because that diminishes the rest of the team. Better to say something like "As one of the two team members with a strong engineering background, my particular role was.."