Getting a runtime waning, division by zero in error function and also plot of error is also not correct

[KaNishk-SiNghal-2236931373079623 (KaNishk SiNghal)]

err += y_true[i] * np.log2(hx) + (1-y_true[i])*np.log2(1-hx)

this line is giving division by zero warning

Jupyter Notebook file drive link:

chemical_separation.ipynb