How to produce a double plot in a single figure where you change only the first input and others remain constant

%Input Data Pm=20; PV=7; YP=7; ROP=54; Dcut=0.175; Dp=2.375; Dh=5; %Cutting Velocity Dra=(Dp/Dh)^2; Cc=(0.64+(18.16/ROP)); Vcut=1/((1-Dra)*(Cc)); %Assume Vs1 Vs1=1; Vss=Vs1; n=0; while(Vss-Vs1)<=0.01 Vmin=Vs1+Vcut; %Apparent Viscosity Ua=PV+((5*YP*(Dh-Dp))/Vmin); % Calculate Vss if (Ua<53) Vss=(0.00516*Ua)+3.006; else Vss=0.02554*(Ua-53)+3.28; end n=n+1; end %Angle correction factor Ang=(55:1:90); Cang=(0.0342*(Ang))-(0.000233*(Ang.^2))-(0.213); %Cutting size correction factor Csize=-1.04*(Dcut)+1.286; %Mud wieght correction factor if (Pm>=8.57); Cmwt=(1-0.0333*(Pm-8.7)); else Cmwt=1; end Vslip=(Vss*Cang*Csize*Cmwt); Vcrit=Vslip+Vcut; %plot plot(Ang,Vcrit) grid on title('Graph of Critical Velocity against Angle of Inclination') xlabel('Angle (deg)') ylabel('Velocity (ft/sec)')