Let be skew-Hermitian, i.e, .
Show that is nonsingular.
Well, I know that an arbitrary square matrix can be written as the sum of a Hermitian matrix and a skew-Hermitian matrix.
This tells me that is Hermitian, and since the determinant of a Hermitian matrix is real it is is not singular.
First, is not hermitian in general, as you can easily check by using . Second, even if it were then its determinant is real so...so what? It could be zero as zero is a real number! In fact, the zero matrix is Hermitian, and thus your argument doesn't work.
Now, I would like to express this in an more elegant manner using actual math
Hope someone can give me a hint or two, thanks.