I have to write a program which will calculate using false position method the maximum of a given equation. And at the end I need to return the root and a value of the function at that point. I am not getting the answer can anyone help? )

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Daniel Stankowski 2018-3-29

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https://ww2.mathworks.cn/matlabcentral/answers/391492-i-have-to-write-a-program-which-will-calculate-using-false-position-method-the-maximum-of-a-given-eq

回答： Daniel Stankowski 2018-4-1

 %The root should be equal to 225, at least thats what i got when i did same question using bisection method
function [ xr ] = false_position( f,g, xl, xu )
w=1.75;
E=5*10.^5;
I=3*10.^5;
L=450;
g=@(x)(w/(120*E*I*L))*(-x.^5+2*L.^2*x.^3-L.^4*x);%orignal
f=@(x)(w/(120*E*I*L))*(-5*x.^4+6*L.^2*x.^2-L.^4);%derivative
xl=0;
xu=L;
if f(xl)*f(xu)>0
    disp('error wrong end points')
else
    xr=(xl*f(xu)-xu*f(xl))/(f(xu)-f(xl));
    error=abs(f(xr));
    while error>1e-4; 
        if f(xr)>0
            xu=xr;
        else
            xl=xr;
        end
         xr=(xl*f(xu)-xu*f(xl))/(f(xu)-f(xl));
         error=abs(f(xr));
    end
    fprintf('The point of maximum deflection is: %f\n', xr);
    fprintf('The value of maximum deflection is: %f\n',g(xr));
end*

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James Tursa 2018-3-29

Do not post screen shots of code. We can't copy & paste screen shots into MATLAB to run. Please remove your screen shot and replace it with text of your code (and use the { } Code button to format your code as well).

Daniel Stankowski 2018-3-30