The above problem was asked in my class test. I understand that this waveform has a hidden symmetry.
x(t) = Square wave with p-p A + (A/10)
So, I can write fourier series expansion for it. As square wave contains odd half wave symmetry, so only odd harmonics of sin are present.
x(t) = sum[(2A/npi)sinnwt] + (A/10)
I am stuck here. How can I draw amplitude and phase spectrum from here?
A plot will be really helpful to understand.