How can I find solutions included in an interval ??

I am trying to solve an equation of one unknown Z using fsolve.

Let us say that the value of the guess for Z is 610 and that I am using the writing: fsolve(@eqns,610).

Which writing should I use to find only the solutions Z which are included in the interval [600 670] ??

Answer 1

[Walter Roberson]

   fzero(@eqns, [600 670])

Notice that is fzero, not fsolve.

Warning: in order for fzero to work on an interval, the equation evaluated at the two endpoints must have different signs.

[kamal kiki]

Thank you very much Walter Roberson.

Really the problem of sign difference is a big problem.

Is there any solution to that ???