# Science:Math Exam Resources/Courses/MATH215/April 2014/Question 03 (b)/Statement

A small mass can move along the x-axis between two large masses located at ${\displaystyle x=-1}$ and ${\displaystyle x=2}$. When subjected to a linear drag its position ${\displaystyle s(t)}$ obeys the differential equation:
${\displaystyle \displaystyle s''(t)={\frac {-1}{(s+1)^{2}}}+{\frac {4}{(s-2)^{2}}}-s'(t),\quad -1