Hi @SubtainSajid-s9m, We appreciate the comment and always like when people keep an eye out for errors. Your first comment is valid for what is shown in the original video. This has already been noted in the description, and updated in CalcBook some time ago. We would also like to note that the use of cosine resulted in overly conservative results. Your second comment is not an error, but follows the guidance of chapter F11 of AISC 360-22. Equation (F11-1) specifies a factor of 1.5 for rectangular members which is what is being checked here. Equation (F11-2) specifies a factor of 1.6, but this only applies to rounds, which is not applicable here. Note, this video covers the 16th edition, AISC 360-22. Your second comment would be valid for the 15th edition, AISC 360-16, but they updated to 1.5 for rectangular bars in the 16th edition, AISC 360-22.
