The Fourier series expansion of sgn(cos(t)) has _________. Where sgn represents the signum function

only cosine terms with even harmonies.

only sine terms with even harmonies.

only sine terms with odd harmonies.

only cosine terms with odd harmonies.

The Fourier series expansion of sgn(cos(t)) has _________. Where sgn

1.	The Fourier series expansion of sgn(cos(t)) has _________. Where sgn represents the signum function
A.	only sine terms with even harmonies.
B.	only sine terms with odd harmonies.
C.	only cosine terms with odd harmonies.
D.	only cosine terms with even harmonies.
Answer» D. only cosine terms with even harmonies.