Based on this question,

Does it means I need to find the five smallest roots on the positive $x$ axis?
What interval would these roots lie on?
Based on this question,

Does it means I need to find the five smallest roots on the positive $x$ axis?
What interval would these roots lie on?
Maybe some network problems make me can not open your website. This is a transcendental equation. I try to solve this problem by WolframAlpha, here is the answer https://www.wolframalpha.com/input/?i=x%3Dtanx
I think it is not easy to find the specific roots. If you find some interesting ideas please let me know.