How to plot after finding roots?

%% Sir, I have multy equation function and try to find roots and plot. functions are

w=abs(ww)

A±=w/a±b

f1=aone*sgn(ww)*[sqrt(1-A+^2)*heaviside(1-A+^2)-sqrt(1-A-^2)*heaviside(1-A-^2)]

f2=bone*sgn(ww)*[1+sgn(A+)*sqrt(A+^2-1)*heaviside(A+^2-1)-sgn(A-)*sqrt(A-^2-1)*heaviside(A-^2-1)]

f=f1+i*f2 %% complex function

f3=(1+Af)*(1+bf)-C^2f^2

%% I wants roots with respect to w and plot between w and b

%% but there is error for both roots and plting

%% for finding roots i try "solve(f3,w)" but got error "Empty sym: 0-by-1"

%% please tell me about above