Please help to rectify an error......(Error in while loop)

b=5; x1=0; x2=0.5; x3=1; dx=0.5; % Initial values
syms x
f=inline('(x^2)+(54/x)'); % Function

while x3<=b                     %Conditions
if f(x1)>=f(x2) && f(x2)<=f(x3) %Conditions
disp('minima lies between x1 and x3')
else 
x1=x2; x2=x3; x3=x2+dx; % Modified values of x1 x2 & x3 if above condition is not satisfied. 
                        % from these values it should goto start point until conditions are satisfied 
end
end

Answer 1

[Walter Roberson]

You have not defined dx.

You are not using "x" so "syms x" is not needed.

[Maruti Patil]

dx=0.5; i forgot to write in question

[Walter Roberson]

As soon as the condition

if f(x1)>=f(x2) && f(x2)<=f(x3)

becomes true, it stays true because you do not alter any values in the body of the "if", only in the body of the "else". As you do not make any change to x3 when the condition holds, your "while" remains true, the if succeeds again, nothing changes, the while stays true....

You might want a "break".

[Maruti Patil]

Thank you Walter Roberson break is working...