If you mean "does a 44khz only output a square (or triangle) wave at 22kHz, the answer is "no."
If you have two alternating values at 44kHz, the output will be a perfect (to the limits of noise &c.) sine wave, since the DAC is band limited.
If this is still confusing to you, I recommend watching https://www.youtube.com/watch?v=FG9jemV1T7I
If you mean "does a 44khz only output a square (or triangle) wave at 22kHz, the answer is "no."
If you have two alternating values at 44kHz, the output will be a perfect (to the limits of noise &c.) sine wave, since the DAC is band limited.
If this is still confusing to you, I recommend watching https://www.youtube.com/watch?v=FG9jemV1T7I