normalisable wavefunction造句

My question-Why "'square "'the amplitude ? ( I think this is what is happening-see the Wikipedia article " Normalisable wavefunction " )-I know that squaring makes the mathematics more convenient ( gets rid of negatives and also gives a convenient sum of 1 when squaring components sine and cosine ) But I'm still left with the basic question-why the square?
It's difficult to find normalisable wavefunction in a sentence. 用normalisable wavefunction造句挺难的