#2) Graph x^2-y^2-2*x-2*y-1==0
a=plot([-1+sqrt((x-1)^2-1)],2,4,color='red',aspect_ratio=1)
b=plot([-1-sqrt((x-1)^2-1)],2,4,color='blue',aspect_ratio=1)
c=plot([-1+sqrt((x-1)^2-1)],-2,0,color='red',aspect_ratio=1)
d=plot([-1-sqrt((x-1)^2-1)],-2,0,color='blue',aspect_ratio=1)
a+b+c+d