removed typo

src/lecture_2.md

@@ -19,9 +19,9 @@ The learning goals of lecture 2A are to understand:
 - central terms such as mobility and the Hall resistance.
 
 The learning goals of lecture 2B are to understand:
-- how to calculate the electron density of states in 1D, 2D, and 3D using the Sommerfeld free-electron model at T=0.
+- how to calculate the electron density of states in 1D, 2D, and 3D using the Sommerfeld free-electron model.
 - how to express the total number and energy of particles in a system in terms of an integral over k-space.
-- how to use the Fermi function to extend the previous two learning goals to finite T.
+- how to use the Fermi function to extend the previous learning goal to finite T.
 - how to calculate the electron contribution to the specific heat of a solid.
 - central terms such as the Fermi energy, Fermi temperature, and Fermi wavevector.