how to use loop in function to plot

function  y=f(x)
np=1.5;
a=1.2;
b=3;

x=np*sin(theta);

k1=sqrt(a-x^2);
k2=ksqrt(b-x^2);
y=(k1-k2)/(k1+k2);
end

how to determine the delta(y)/ delta(x)/ with the variation of theta;

delta means change in value of parameter how to write using loop

pl help to plot delta(y)/delta(x) vs theta

[Torsten]

Your function makes no sense since theta is undefined in f.

This will throw an error.

[shiv gaur]

Dr torsten you can take the value of theta between 0 to 2*pi yo are req to help in earlier problem also thanks

[Walter Roberson]

how to determine the delta(y)/ delta(x)/ with the variation of theta;

x is a function of theta, so you are asking to take the derivative of function y with respect to function x,

Answer 1

[Walter Roberson]

syms x(theta)
np=1.5;
a=1.2;
b=3;

X=np*sin(theta);

k1=sqrt(a-x^2);
k2=sqrt(b-x^2);
y=(k1-k2)/(k1+k2);

dydx = functionalDerivative(y,x)

dydx(theta) = 

dydtheta = simplify(subs(dydx, x, X))

dydtheta(theta) = 

fplot(dydtheta, [-2*pi 2*pi])

Answer 2

[Mathieu NOE]

hello

try this

I modified your function because x and y are both outputs

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

figure(1)
[x,y]=f(theta);
dx = gradient(x);
dy = gradient(y);
plot(theta,dy./dx);


%%%%%%%%%%%%%%%%%%%
function  [x,y]=f(theta)
    np=1.5;
    a=1.2;
    b=3;
    x=np*sin(theta);
    k1=sqrt(a-x.^2);
    k2=sqrt(b-x.^2);
    y=(k1-k2)./(k1+k2);
end

[shiv gaur]

if three variable are there what will be change in program pl modified this

[shiv gaur]

sir we modified the program like that

theta = linspace(0,2*pi,100);
figure(1)
[x,y]=f(theta);
dx = gradient(x);
dy = gradient(y);
plot(da,dy/dna./dx/dna);
%%%%%%%%%%%%%%%%%%%
function  [x,y]=f(theta)
np=1.5;
nb=2;
x=np*sin(theta);
k1=sqrt(na^2-x.^2)+na;
k2=sqrt(nb^2-x.^2)+da;
y=(k1-k2)./(k1+k2);
end

so to calculate the dy/dx is written as dy/dx =dy/dna /dx/dna so there are three

gradient and fourth one is da so you are requested to plot in this manner vs da

pl