Final answer:
The bass note in a first inversion E augmented triad is E.
Step-by-step explanation:
In a first inversion E augmented triad, the bass note is the root note, which is E. An augmented triad consists of the root note, the major third, and the augmented fifth. In first inversion, the root note is moved to the top of the chord, so the bass note becomes the root note.