plot the graph of mulivariable

theta = linspace(0,2*pi,100);

na= linspace(1,20,100);

da= linspace(0,5,100);

figure(1)

[x,y]=f(theta,na,da);

dx = gradient(x);

dy = gradient(y);

dna=gradient(na);

p=dy./dx/dy./dna;

plot(da,p);

%%%%%%%%%%%%%%%%%%%

function [x,y]=f(theta,na,da)

np=1.5;

a=1.2;

b=3;

x=np*sin(theta);

k1=sqrt(a-x.^2)+na;

k2=sqrt(b-x.^2);

y=(k1-k2)./(k1+k2)+da;

end

pl help to plot graph between da vs p=dy/dx/dy/dna

[shiv gaur]

pl help to plot graph between da vs p=dy/dx/dy/dna

[Benjamin Thompson]

y and dy have complex values due to x being to large. Can you change the definition of your problem?