# whats problem in my code for solve newton Rhapson method for equation 4-x^2-y^2 1-exp(x)-y

16 views (last 30 days)
clc
clear
format long
n=10; x(1)=1; y(1)=-1.7;
for i=1:n
f(x(i),y(i))=4-x(i)^2-y(i)^2;
g(x(i),y(i))=1-exp(x(i))-y(i);
fx(i)=4-2*x(i);
gx(i)=-exp(x(i));
fy(i)=-2*y(i);
gy(i)=-1;
x(i+1)=x(i)-(f(i)*gy(i)-fy(i)*g(i))/(fx(i)*gy(i)-fy(i)*gx(i));
y(i+1)=y(i)-(fx(i)*g(i)-f(i)*gy(i))/(fx(i)*gy(i)-fy(i)*gx(i));
end

Walter Roberson on 3 Dec 2020
Suppose we could find some way to make your assignments to f(x,y) and g(x,y) work out. Then what would you do with the results? You never use f(x,y) or g(x,y) in your calculations: you only use f(i) and g(i) . Perhaps you should not be assigning to f(x(i),y(i)) and g(x(i),y(i)) and should be assigning to f(i) and g(i) ? for loop doesnt run and i want value of f and g apper and enter in loop for print root of x and y
Walter Roberson on 3 Dec 2020
Repeating myself:
Perhaps you should not be assigning to f(x(i),y(i)) and g(x(i),y(i)) and should be assigning to f(i) and g(i) ?