Как убрать асимптоты на графике?

restart;
with(linalg):
> M:=matrix(4,4,[[phi1-tau,phi2,phi3,phi4],[z^4*phi4,phi1-tau,phi2,phi3],[z^4*phi3,z^4*phi4,phi1-tau,phi2],[z^4*phi2-F*tau,z^4*phi3,z^4*phi4,phi1-tau]]):
> P:=collect(simplify(det(M)),tau):
> phi1:=(cosh(z*t)+cos(z*t))/(2):
> phi2:=(sinh(z*t)+sin(z*t))/(2*z):
> phi3:=(cosh(z*t)-cos(z*t))/(2*z^2):
> phi4:=(sinh(z*t)-sin(z*t))/(2*z^3):
> F:=(z^3*(4*(cosh(z)+cos(z))*cos(theta)-cos(2*theta)-4*(1+2*cosh(z)*cos(z))))/((-sinh(z)+sin(z))*(cos(theta)/2)+(2*cos(z)*sinh(z)-2*cosh(z)*sin(z))):
> R:=subs(t=1,collect(simplify(P), tau)):
> simplify(coeff(P, tau, 3)-coeff(P, tau, 1)):
> simplify(coeff(P, tau, 4)-coeff(P, tau, 0)):
> A:=simplify(coeff(R,tau,1)):
> B:=simplify(coeff(R,tau,2)):
> for i from 0 to 10 by 1 do
> theta:=Pi*i/10:
> F1[i]:=subs(t=1,simplify(simplify((-A+sqrt(A*A-4*(B-2)))/4))):
> F2[i]:=simplify(subs(t=1,((-A-sqrt(A*A-4*(B-2)))/4)),'size'):
> od:
> z:=lambda^(1/4):
> plot([F1[0],F1[1],F1[2],F1[3],F1[4],F1[5],F1[6],F1[7],F1[8],F1[9],F2[0],F2[1],F2[2],F2[3],F2[4],F2[5],F2[6],F2[7],F2[8],F2[9],-1,1], lambda=0..1000, -2..2):
> plot([F1[0],F1[1],F1[2],F1[3],F1[4],F1[5],F1[6],F1[7],F1[8],F1[9],F2[0],F2[1],F2[2],F2[3],F2[4],F2[5],F2[6],F2[7],F2[8],F2[9],-1,1], lambda=0..1000, -2..2,discont=true);