this is bisection method in link below: https://docs.google.com/spreadsheets/d/1c9FvwA-l3XIkO4W1onp5Gq2lg3tmduUkxf9V1MNIKzs/edit#gid=0
and this is python code using google colab:
https://colab.research.google.com/drive/1PMwQ2bm-K8105C96kNBYj4-fz9kF-IRY#scrollTo=XeVmT4CJ0azw