how can i find When function is zero without Functions like fzero solve ...?

help me please

[Jan]

Please mention the background of this question. Maybe all you want is index = (x==0) or find(y==0), or you want to write a pseudo-newton method with a line-search and an internal numerical approximation of the 2nd derivatives. There are many different solutions with different properties.

[arkadi ak]

i have a task to find the Cutting points of two Functions without using Functions like fzero solve

[Jan]

@arkadi ak: Now it matters if this is a homework of a lesson of the beginners course of numerical maths, or if this is a PhD thesis. It matters if you want a cheap solution of 1D functions, or if you talking about a mutli-dimensional case.

I ask you again for posting more details. Give us a chance to help you.

[OCDER]

Before anyone can help, you'll have to be more clear about these:

What are the two functions and their inputs and outputs? Do you mean to find the intersection point(s) of two "equations"? And why can't you use fsolve? Is this an assignment to make an algorithm like fsolve? If so, what matlab code have you written or are having trouble with? What "answer" do you want from the forum - pseudo code or hints about matlab functions to use?

[arkadi ak]

It's one-dimensional functions same as f1=x^3+5x f2=x^7+2 //f1=sinx+e^x f2=cosx Or something like that

[arkadi ak]

yes i need the intersection of the equations and i like a code . i cant use fsolve Because The teacher wants that we find the intersection points without ready Functions.

[Guillaume]

Because The teacher wants that we ...

Most likely, the teacher also wants that you come up with and write the algorithm yourself, not copy/paste it off some website.

[arkadi ak]

i take matlab course for Beginners and it is small Part of the assignment

[Steven Lord]

Even if it is a small part of an assignment, it's still part of an assignment and it's probably part of that assignment because your professor thinks it valuable for you to do.

If you show us what you've tried so far and ask a specific question about where you're having difficulty we can offer suggestions. If you're not sure even how to get started, you should speak to your professor and/or your teaching assistant for help with the initial setup.

[arkadi ak]

At first I was thinking of Newton method and the teacher said use Other method ,I thought of a point before and after Then I understood thet i can miss out a Points .

Answer 1

[Jan]

I'm sure you have heard something about method to find roots of functions. Perhaps a Newton-Raphson method? Or Regula-False, bisection method, etc. Then it is likely that your teacher wants you to implement the method you have learned in the lessons. The forum can, will and should not do this for you, because it is not our homework and we did not know, what you have been taught.

See also: https://en.wikipedia.org/wiki/Root-finding_algorithm

[arkadi ak]

Not really i need it for matlab course for Beginners

[Jan]

If your teacher tells you to use "another" method, read the list of possible methods from the given link and ask your teacher again, which one he will accept. We cannot guess what your teacher wants, but you can ask him or her.