Fourier series approximation: DC component and fundamental frequency In the linked image below, what is meant by plotting the DC component and fundamental frequency for a Fourier series approximation?


  


For dot point 1 does it want me to graph just the DC component basically or for the first harmonic? Basically what is meant by fundamental frequency?
Plotting the DC component and only the fundamental frequency means, you should plot the harmonic approximation that uses only $a_0, a_1, b_1$ (i.e. the DC component plus sines and cosines of the first frequency (which is the fundamental frequency). For the second point, you should plot the reconstruction with $a_0, a_1, b_1, a_2, b_2$. 

Exactly this problem is treated, including code, at my site.