According to the equations of marginallystable idealMHD, (2.375)–(2.380), the electron number density, the electron temperature,
and the ion temperature all satisfy equations of the form

(3.39) 
Linearization of the previous equation yields

(3.40) 
where denotes an equilibrium quantity. It follows from Equations (3.8), (3.19), and (3.32) that

(3.41) 
More explicitly, we conclude that the perturbations in the electron number density, the electron temperature,
and the ion temperature that are associated with a tearing mode in a low, large aspectratio, tokamak plasma take the respective forms