To write the inversion of the interval of the 2nd, 3rd, and 1st using treble staff, you would need to specify which notes you are starting with and which key you are in. Without this information, it is not possible to complete this task.
To build a tonic triad with first and second inversion, you would need to choose a root note and a key signature. For example, in the key of C major, the tonic triad is C-E-G. To build a first inversion of this triad, you would rearrange the notes to E-G-C. To build a second inversion, you would rearrange the notes to G-C-E.
The enharmonic equivalent of C# is Db, the enharmonic equivalent of F# is Gb, the enharmonic equivalent of B# is C, and the enharmonic equivalent of G# is Ab.
To construct the ascending and descending scale of D major, with the key signature and marking the semitones with slurs, you would write the following:
Ascending: D | E | F# | G | A | B | C# | D
Descending: D | C# | B | A | G | F# | E | D