finding roots of the equation

25 views (last 30 days)
mohammad
mohammad on 10 Feb 2012
For several value of n (n=1,2,3,4,...), it was needed to find roots of under equation.
f(n,I)=n*210+(I^2/n)*[(((200-32I)^2)/200)+32]-197
Please help me, how can I find answer by using MATLAB. And please give me answers (value of I) for n=1,2,3,4,5

Accepted Answer

Matt Tearle
Matt Tearle on 10 Feb 2012
You may want to check your function, because it doesn't seem to have any (real) zeros:
f = @(n,I) n*210+(I.^2/n).*((((200-32*I).^2)/200)+32)-197;
figure
I = linspace(-100,100,5001);
y = f(1,I);
plot(I,y)
min(y)
But, the approach would be to define a function handle for f, as above, then set the value of n and apply fzero to the resulting function of one variable ( I ):
f = @(n,I) n*210+(I.^2/n).*((((200-32*I).^2)/200)+32)-197;
I0 = 0; % Make an initial guess
for n = 1:5
g = @(I) f(n,I); % Make a new function from f(n,I) with n fixed
I0 = fzero(g,I0) % Find zero, starting with previous result
end
  2 Comments
mohammad
mohammad on 10 Feb 2012
thanks let me check

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by