SetOptions[Plot,PlotStyle->{Black,AbsoluteThickness[2]},BaseStyle->{16}];

Parameters come form the LRC circuit lab are R=100 ohms, L=140 mH = 0.14 H, C=0.1 µF = 10^-7 F.
Parameterd for the class demo are

R=100;
L=.140;
C0=10^(-7);
ω0=1/Sqrt[L*C0]
f0=ω0/2/π
β=R/2/L
Y[ω_]:=(ω/L)/Sqrt[(4*β^2*ω^2+(ω0^2-ω^2)^2)]
ϕ[ω_]:=π/2+ArcTan[(ω0^2-ω^2),-R*ω/L]
Plot[Y[ω], {ω,0, 3 ω0},PlotRange->All,AxesLabel->{"ω (rad/s)","mod Y"},Ticks->{{{ω0,(Subscript[ω, 0])},{2ω0,2(Subscript[ω, 0])},{3ω0,3(Subscript[ω, 0])}},None}]
Plot[ϕ[ω], {ω,0, 3 ω0},PlotRange->{-π/2,π/2},AxesLabel->{"ω (rad/s)","phase(Y)"},Ticks->{{{ω0,(Subscript[ω, 0])},{2ω0,2(Subscript[ω, 0])},{3ω0,3(Subscript[ω, 0])}},{-π/2,0,π/2}}]

p=1/2;
T=2 π/(ω0);
Vtriangle[t_]:=Sum[(4/n^2/π^2)*(1-(-1)^n)*(Cos[n*p*2 π t/T]),{n,1,15}]
Itriangle[t_]:=Sum[(4/n^2/π^2)*(1-(-1)^n)*Y[n*p*2 π /T]*(Cos[n*p*2 π t/T+ϕ[n*p*2 π /T]]),{n,1,3}]
Plot[Vtriangle[t] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)","Vtri"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]
Plot[R*Itriangle[t] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)","Itri"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Blue,AbsoluteThickness[2]}]
Plot[{Vtriangle[t],20*R*Itriangle[t]} ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

p=1
T=2 π/(ω0);
Vsquare[t_]:=Sum[(2/n/π)*(1-(-1)^n)*(Sin[n*p*2 π t/T]),{n,1,13}]
Isquare[t_]:=Sum[(2/n/π)*(1-(-1)^n)*Y[n*p*2 π /T]*(Sin[n*p*2 π t/T+ϕ[n*p*2 π /T]]),{n,13}]
Plot[Vsquare[t] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)","Vsq"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]
Plot[R*Isquare[t] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)","Isq"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Blue,AbsoluteThickness[2]}]
Plot[{Vsquare[t],R*Isquare[t]} ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

n3=3;
T=2 π/ω0;
ϕ[n3 ω0]
V3[t_]:=(1/3)*Exp[I*n3*2 π t/T];
curr3[t_]:=Y[n3 ω0]*Exp[I*ϕ[n3 ω0]]*V3[t];
Plot[{Re[V3[t]],Re[curr3[t]]} ,{t,0, 3T},PlotRange->{-2,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}}, PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

n1=1;
T=2 π/(ω0);
V1[t_]:=Exp[I*n1*2 π t/T];
ϕ[n1 ω0]
curr1[t_]:=Y[n1 ω0]*Exp[I*ϕ[n1 ω0]]*V1[t];
Plot[{Re[V1[t]],Re[curr1[t]]} ,{t,0, 3T},PlotRange->{-2,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}}, PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

n2=2;
T=2 π/(ω0);
V2[t_]:=-1*Exp[I*n2*2 π t/T];
ϕ[n2 ω0]
curr2[t_]:=Y[n2 ω0]*Exp[I*ϕ[n2 ω0]]*V2[t];
Plot[{Re[V2[t]],Re[curr2[t]]} ,{t,0, 3T},PlotRange->{-2,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}}, PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

V[t_]:=V1[t]+V2[t]+V3[t]
curr[t_]:=curr1[t]+curr2[t]+curr3[t]
Plot[{Re[V[t]],Re[curr[t]]} ,{t,0, 3T},PlotRange->{-2,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{{Red,AbsoluteThickness[2]},{Blue,AbsoluteThickness[2]}}]

V[t_]:=V1[t]+V2[t]+V3[t]
Plot[Re[V[t]] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]

Vtriangle[t_]:=Sum[(2/n^2/π^2)*(1-(-1)^n)*(Exp[I*n*2 π t/T]+Exp[-I*n*2 π t/T]),{n,1,3}]
Vtriangle[0]
Plot[Vtriangle[t] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)",None},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]

p=1/2
Vtriangle[t_]:=Sum[(4/n^2/π^2)*(1-(-1)^n)*(Cos[n*p*2 π t/T]),{n,1,7}]
Itriangle[t_]:=Sum[(4/n^2/π^2)*(1-(-1)^n)*Y[n*p*2 π /T](Cos[n*p*2 π t/T+ϕ[n*p*2 π /T]]),{n,1,7}]
Itriangle[T/2]
Plot[Re[Vtriangle[t]] ,{t,0, 3T},PlotRange->{-2.5,2},AxesLabel->{"t (s)","Vtri"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]
Plot[Re[Itriangle[t]] ,{t,0, 3T},PlotRange->All,AxesLabel->{"t (s)","Itri"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]

This next section is about the sawtooth wave and shows that the series is different if you choose a different time origin even if the finction is always odd.

Vsawtooth[t_]:=Sum[(2/n*π)*(Sin[n*2 π t/T]),{n,1,2}]
Plot[Vsawtooth[t] ,{t,0, 3T},PlotRange->{-10,10},AxesLabel->{"t (s)","Vsaw"},Ticks->{{{T,"(Subscript[T, 0])"},{2T,"2(Subscript[T, 0])"},{3T,"3(Subscript[T, 0])"}},{-1,1}},PlotStyle->{Red,AbsoluteThickness[2]}]