Code to get first n roots of a function

I have to find first n roots of a function however I am unable to do so using fsolve or fzero or optimization toolbox which give wrong answers and moreover , they give a single root at a time so I am unsure of how to use them for n iterations, the function looks like this:

It behaves pathetically after the blue arrows and I have difficulty in getting the roots, sometimes the roots are also very close together.

So I wanted to know how to get this task done?

[Ameer Hamza]

How is the function defined? What if you give the initial guess close to the required point.