The question wants me to first estimate the roots by drawing the graph and then by using a 'suitable' fixed point method to determine the first 4 positive roots.
I rearranged to get x=arctan (x) so that the series x_n will converge.
The Attempt at a Solution
I've attached my code. My lecturer told us to reuse some code in the lecture notes and just modify it for this function but I don't fully understand what it's doing. My main problem is the f_old and f_new parts. That was my attempt at changing what was in the book (the book had a different function so I had to modify this for my function) but I don't know how they're useful.
Anyway, if I let the code run, my x_new and f_new go to zero which I think means that it's honing in on the x=0 root. The next root is about x=4.5 or so but if you add pi to 0 then you get pi and not the next root (x=4.5). What am I missing?